Abstract:
An improved energy capacity brake employing a drum structure with dual braking surfaces may be utilized in a wide variety of industrial and commercial applications requiring braking action. The drum includes first and second annular drum parts joined together to provide a dual drum feature for use with a coupling component together forming a drum brake assembly. In an alternate embodiment the drum may be cast with a single disc member having two braking surfaces.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims benefit pursuant to 35 U.S.C. §119(e) of U.S. Provisional application 61/828,711, filed May 30, 2013, which is herein incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     The present disclosure relates to an improved energy capacity brake employing a dual drum utilized in a wide variety of industrial and commercial applications requiring braking action, and is particularly suited for high energy applications. 
     Industrial brakes are employed as an emergency brake or even as a torque limiter, for example, in wind turbines. The brake assembly requires the ability to absorb a significant amount of heat energy and for a long period of time. Heat is generated during the braking action and this heat needs to be dissipated or absorbed in an efficient manner to prolong the life of the brake assembly, a gear box, or a generator in high wind conditions or a grid failure condition. In these types of braking actions requiring large energy capacities, the size of the brake has to be large or else some type of cooling systems required to consume the heat generated during the braking action. 
     There still exists a need for an improved brake having the capacity to handle the energy from the heat generated during an emergency braking action or torque limiting actions for an application requiring such in order to protect the associated equipment with that application and prolong the life of the brake assembly. 
     SUMMARY 
     The present disclosure describes an improved high energy ventilated dual brake drum that may be employed with a drum brake assembly that has utility as a brake or a clutch for applications requiring absorption of heat energy. 
     The present disclosure discloses an improved drum for a drum brake assembly that includes a first annular drum part having a first base member and a second disc member. The first base member of the first annular drum part extends axially outward in a first direction. The second disc member of the first annular drum part is angularly connected to the first base member of the first annular drum part. The second disc member extends radially inward from the first base member. The first base member has an annular outer surface that is constructed to receive and engage at least a portion of a friction element thereon from a coupling component. The drum also includes a second annular drum part having a first base member and a second disc member. The first base member of the second annular drum part extends axially outward in a direction opposite that of the first base member of the first annular drum part. The second disc member of the second annular drum part is angularly connected to the first base member of the second annular drum part. The second disc member extends radially inward from the first base member at a similar angle to that of the second disc member of the first annular drum part. When the second disc member of the first annular drum part and the second disc member of the second annular drum part are connected, together they form the improved dual brake drum according to the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective elevation view with a portion omitted depicting a drum brake assembly; and 
         FIG. 2  is a perspective elevation view similar to  FIG. 2  of the improved high energy ventilated dual drum brake according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the Figures, where like numerals designate like or similar features throughout the several views, and which are not intended to limit the present disclosure,  FIG. 1  illustrates a coupling component, generally designated  10 , for a drum brake assembly. The term “brake assembly” and “braking action” as used herein is meant to include having the ability to function as a clutch or a clutch assembly. In  FIG. 1 , the coupling component generally designated  10  may include an inflatable tube  12  and an annular array of friction elements  14  on backing plates. Tube  12  has a generally flattened annular structure. One or more reinforced and/or non-reinforced layers may be disposed in or around tube  12  to enable the coupling component  10  to withstand relatively large torque forces. While a range of elastomers, including thermoset and thermoplastic elastomers, may be used to construct the tubel 2 , thermoplastic elastomers provide a good blend of efficiency and integrity when joining the two ends of the tube  12 . A conduit (not shown) directs fluid pressure, for example air pressure, into the annular tube  12  causing the tube  12  to expand radially inwardly for engaging the plurality of friction elementsl 4  against the drum  20 . 
     Upon inflation, tube  12  expands causing friction elements  14  to constrict radially inwardly causing the radially inner surfaces of the friction elements  14  to frictionally engage an outer surface  21  of drum  20 . The friction between the friction elements  14  and the drum  20  couple the drum  20  and the coupling component  10  together to form the drum brake assembly generally designated  8  as seen in  FIG. 1 . The resulting torque forces may retard or stop the motion of the drum  20  resulting in the generation of heat energy. When brake assemblies are used as emergency brakes or torque limiters, for example in wind turbines or other high energy applications, the brake assembly needs to absorb or dissipate this generated heat energy for a fairly long period of time to protect the gear box and generator during high wind conditions or in the event of a grid failure or simply due to the application. An advantage of the brake assembly of the present disclosure is its ability to act as a heat sink and absorb this heat energy without the need to build a huge brake assembly. In many instances where a brake assembly needs to be used in high heat energy applications the brake assembly&#39;s size is dramatically increased for the torque. As a result this also increases the space requirement and cost. If flowing water or another fluid is used to cool the brake assembly, the additional power source, pump, valves, and conduits add tremendously to the cost and size requirements. 
     While the single drum  20  shown in  FIG. 1  has found use in the industry, it is limited in its ability to absorb heat energy and its applications. The improved ventilated dual brake drum  40  of the present disclosure increases thermal capacity and service ability. The configuration of the dual brake drum  40  increases heat sink by increasing mass support in the middle of the drum and its ventilating characteristics. 
     In  FIG. 2 , there is depicted the improved ventilated dual brake drum  40  according to the present disclosure in position within a coupling component  10  together forming an improved drum brake assembly generally designated  30 . Drum  40  comprises a first annular drum part  42  and a second annular drum part  44 . The first annular drum part  42  includes a first base member  46  and a first disc member  48 . The first base member  46  is attached to the first disc member  48  in a manner that projects the first base member  46  substantially at a right angle from the first disc member  48 . That is the first base member  46  extends axially away from the first disc member  48 . The first disc member  48  extends radially inward as seen in  FIG. 2 . The first disc member  48  includes a centrally located opening  50  for receiving a shaft or other component requiring braking from a workpiece (not shown). First disc member  48  also may include a plurality of ventilating apertures  52  and passages  54  which may be used for connection to a hub  62  with fasteners  60 . 
     The second annular drum part  44  likewise includes a second base member  56  and a second disc member  58  joined together in a similar manner as that of the first base member  46  and first disc member  48  except that the second base member  56  of the second annular drum part  44  is axially oriented in an opposite direction to that of first base member  46  of the first annular drum part  42 . The second disc member  58  of the second annular drum part  44  includes a centrally located opening  50  that is concentric with that of the first disc member  48  of the first annular drum part  42 . The second disc member  58  further includes ventilating apertures  52  and passages  54  that may be concentric with those of the first disc member  48 . 
     The first annular drum part  42  may be attached to the second annular drum part  44  with a plurality of fasteners  60  through passages  54 . Alternatively, the two drum parts  42 ,  44  may be joined together by welding or other suitable means, or cast as a single unit. Together the two disc members  48 ,  58  may include the hub  62  having a centrally located opening  64  that may be concentric with opening  50  and may be attached to the hub  62  with fasteners  60  through a plurality of holes  66  in the hub that are coincident with the passages  54 , or in any other suitable manner. 
     The drum  40  and its first and second annular drum parts  42 ,  44  are made of a metal, like iron, steel or a metal alloy or other suitable material for the desired application. The braking surface of the drum  40 , that is the first and second base members  46 ,  56  may include special treatment such as coating or implantation of hardening metals or ceramics or cladding with a wear resistant material. Drum  40  may also include friction shield elements on its outer surface of the first and second base members  46 ,  56 . 
     Upon inflation of the annular tube  12  with a suitable fluid, like air, the annular tube  12  causes friction elements  14  to move radially inwardly, or to constrict against the outer surface of the first base member  46  of the first annular drum part  42  and the first base member  56  of the second annular drum part  44 , respectively, for the braking action. Together the outer surfaces of the base members  46 ,  56  form the braking surface of the drum  40 . 
     While the drum has been described as including first and second annular drum parts  42 ,  44 , it should be immediately apparent that the drum of the present disclosure may be cast as a single unit with a single disc member  48 ′ and two base members  46 ,  56  extending in opposite directions. This embodiment is similar to that depicted in  FIG. 2  with the exception that there would only be a single disc member  48 ′ rather than the first and second disc members  48 ,  58  as shown. 
     The exemplary embodiments have been described with reference to the present practice. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the exemplary embodiment be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.