Abstract:
The present invention provides an exhaust chamber system, comprising a stationary propeller type blade assembly with a nose cone within or adjacent to an expansion chamber, to create a vortex that swirls exhaust gas towards the outlet. The resultant vacuum within the exhaust chamber aids in scavenging an internal combustion engines exhaust gases, and in reducing system back pressure The exhaust chamber maintains the sound level of the exhaust within acceptable limits, while delivering improved horsepower, torque, and/or fuel efficiency over standard and other performance mufflers.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention provides an exhaust chamber system for internal combustion engines, which delivers improved horsepower, torque and/or fuel efficiency over standard and other performance mufflers.  
       BACKGROUND AND DESCRIPTION OF THE RELATED ART  
       [0002]     Due to environmental concerns, governmental entities have steadily imposed stricter regulations on the amount and type of exhaust emitted by vehicles powered by the internal combustion engine. Moreover, the amount of noise produced by such engines must also meet stringent standards. The federal and state regulations may improve air quality and decrease noise pollution, however these mandates also produce severe drawbacks because the exhaust emission and sound control devices increase fuel consumption and decrease power production by the affected engines. The exhaust emission and sound control devices hamper engine performance as a result of back pressure of exhaust gas created by the very equipment that muffles the noise and cleans the exhaust gas. Designs of exhaust emission and sound control devices that increase exhaust flow-through will mitigate back pressure on the engine, thereby improving overall engine performance while still meeting demanding governmental environmental standards.  
         [0003]     A number of systems have been proposed to provide a more efficient means of reducing noise and/or air pollution from internal combustion engine exhaust. Examples of such proposed systems are found in U.S. Patents issued to Kojima (U.S. Pat. No. 4,533,015), Michikawa (U.S. Pat. No. 4,339,918), Taniguchi (U.S. Pat. No. 4,331,213), Harris et al. (U.S. Pat. No. 4,317,502), Taniguchi (U.S. Pat. No. 4,303,143), Kasper (U.S. Pat. No. 4,222,456), Everett (U.S. Pat. No. 4,129,196), Lyman (U.S. Pat. No. 4,109,753), Kashiwara et al (U.S. Pat. No. 4,050,539), and Iapella et al (U.S. Pat. No. 3,016,692), amongst others. However, none of these prior art references facilitate an improvement in engine power output or fuel efficiency. The quest to decrease noise and exhaust emissions, while off-setting the concomitant degradation of engine performance manifested by decreases in fuel efficiency, horsepower, and torque production, proves to be an ongoing struggle.  
         [0004]     In particular the system proposed by Lyman (U.S. Pat. No. 4,109,753) presents a muffler assembly for substantially dampening acoustical vibrations of engine exhaust gases. The muffler assembly includes a flow control means, such as a diffuser having a centrally disposed baffle with radially extending deflector vanes and axially extending tabs. The diffuser is positioned near the inlet to an apertured louver tube within a loosely compact shell of sound attenuating material. The apertured louver tube has approximately the same cross sectional area as the inlet and outlet tubes. The diffuser has a planer baffle that substantially blocks and restricts the axial flow of exhaust gases along portions of the longitudinal axis of the louver tube, deflects the flow of exhaust gases toward the sound attenuating material and creates a turbulent flow. However, the Lyman muffler assembly fails to improve engine performance (i.e. fuel efficiency, horsepower, torque), and differs from the present invention in terms of blade (sharp versus rounded) and baffle geometry (planer versus cone shaped), expansion chamber cross sectional area (inlet area same as louver tube versus expansion chamber with larger cross section), and exhaust gas flows (turbulent versus contoured) as will be described.  
       SUMMARY OF THE INVENTION  
       [0005]     The present invention provides an exhaust chamber system, comprising a stationary propeller type blade assembly with a nose cone within or adjacent to an expansion chamber, to contour turbulent exhaust gas and swirl the exhaust gas in a vortex fashion towards the outlet. The nose cone and blade assembly are set at varying angles to aid in arcuately shaping the gas flow. The expansion chamber has a larger cross sectional area than either the inlet or outlet, and is perforated with a maximum aperture count for optimized exhaust gas flow so that the swirling exhaust gas is in communication with the materials in the sound suppression sleeve. The spiral of the swirling exhaust gas becomes progressively tighter as the emissions travel through the expansion chamber to the outlet. This vortex generated by the stationary propeller type blade assembly with a nose cone acts to create a vacuum which draws more gases from the exhaust source, thereby reducing back pressure while increasing the exhaust through put of the engine. The exhaust chamber maintains the sound level of the exhaust within acceptable limits, while delivering improved horsepower, torque and/or fuel efficiency over that of standard and other performance mufflers.  
       OBJECTS AND ADVANTAGES OF THE INVENTION  
       [0006]     It is the object of the present invention to provide a novel exhaust chamber system of the character recited for use with internal combustion engines.  
         [0007]     Another object is to provide a novel exhaust chamber system that meets governmental regulations for sound emissions.  
         [0008]     Another object is to provide a novel exhaust chamber system that improves fuel efficiency, engine horse power, and torque over internal combustion engines fitted with standard or other performance mufflers.  
         [0009]     Another object is to provide a novel exhaust chamber system that contours exhaust gases into a vortex with the use of a stationary propeller type blade assembly with a nose cone.  
         [0010]     Another object is to provide a novel exhaust chamber that produces a vacuum that relieves back pressure on the internal combustion engine and aids in scavenging exhaust gas from the system.  
         [0011]     Another object is to provide a novel exhaust chamber system made up of a two piece construction.  
         [0012]     These and other objects and advantages of the invention will become more apparent as this description proceeds, taken in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is an exploded perspective cut away view illustrating the external and internal features of an embodiment of the exhaust chamber system according to the invention.  
         [0014]      FIG. 2  is an exploded side view of an exhaust chamber system having a stationary propeller type blade assembly embodying the invention.  
         [0015]      FIG. 3  is an end close-up view of the stationary propeller type blade assembly of an embodiment of the invention.  
         [0016]      FIG. 4  illustrates the flow of exhaust gas through the exhaust chamber system according to the invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0017]     The invention is described by the following examples. Variations based on the inventive features disclosed herein are within the skill of the ordinary artisan, and the scope of the invention should not be limited by the examples. To properly determine the scope of the invention, an interested party should consider the claims herein, and any equivalent thereof. In addition, all citations herein are incorporated by reference.  
         [0018]     With reference to the accompanying drawings and particularly  FIGS. 1 and 2  an exhaust chamber system  10  is comprised of two major subassemblies an inlet  12  and an exhaust expansion chamber  14 . In the embodiment of  FIG. 1 a  tapered inlet entry end  12   a  is shown, whereas in  FIG. 2 a  substantially flat inlet end  12   b  and/or outlet end  30  are illustrated. Materials used to form exhaust system components are well-known in the art. In an embodiment, the exhaust chamber system casing and the relevant tubes are made from metals such as 304 stainless steel. Methods of attaching the various components are also well-known. For example, coupling points can be formed integrally, such as welded or brazed.  
         [0019]     An inlet tube  12  (either tapered  12   a  in  FIG. 1  or flat  12   b  in  FIG. 2 ) is attached to the proximal end flange  18  of the exhaust expansion chamber  14  with a series of bolts, screws or other suitable fasteners. A distal end  20  of inlet tube  12  is attached directly or indirectly to an exhaust gas source, such as an internal combustion engine (not shown). The interior  22  of inlet tube  12  opens up into an expansion chamber  24  defined by the interior of an expansion chamber tube  26 . In the case of the tapered inlet tube  12   a,  the interior  22  expands to match the radius of the expansion chamber  24  ( FIG. 1 ). Whereas in the case of the flat inlet tube  12   b  the interior  22  stays constant and has a radius smaller the that of the expansion chamber  24  ( FIG. 2 ). The expansion chamber tube  26  is attached substantially coaxially to outer shell  28  of the exhaust expansion chamber  14 . Moreover, expansion chamber tube  26  is attached to outer shell  28  such that the exterior of the expansion chamber tube  26  and the interior of the outer shell  28  combine to define a sound suppression sleeve  16  that surrounds the expansion chamber  24 .  
         [0020]     Sound suppression sleeve  16  is packed with known sound suppression materials. Examples of such materials include fiberglass, glass wool, ceramic, copper wool, copper strands, steel wool, etc. In the preferred embodiment the sound suppression material is high temperature ceramic packing that holds up to 1800 degrees Fahrenheit and is one inch thick. Expansion chamber tube  26  is perforated stainless steel with maximum aperture count for optimized exhaust gas flow ( FIG. 1  cut away) so that the expansion chamber  24  is in communication with the materials in the sound suppression sleeve  16 . In the preferred embodiment, tube  26  has about 50% porosity. In another embodiment, tube  26  has between about 40 to about 80% porosity. In the preferred embodiment, expansion chamber  24  has at least about 2.11 times greater flow cross-sectional area than inlet tube  12   b.  In a further embodiment, expansion chamber  24  has at least about 2 times greater flow cross-sectional area than inlet tube  12   b.  In yet another embodiment, expansion chamber  24  has between about 2 times to about 2.25 times greater flow cross-sectional area than inlet tube  12   b.    
         [0021]     In the preferred embodiment, at the opening to expansion chamber  24 , at an end proximal to inlet tube  12 , a stationary propeller type blade assembly  32  with a nose cone  36  and attached high temperature gasket seal  34  (see  FIGS. 1, 2  and  3 ) rests in the recessed counter bore  38  on the face of the proximal end flange  18  of the exhaust expansion chamber  14 , and is fully secured by a compression fit when the inlet tube assembly  12  is fastened to the exhaust expansion chamber  14 . The use of the tapered inlet tube  12   a  increases the surface area of the gas flow prior to interacting with the blade assembly  32  with the nose cone  36 , versus the flat inlet  12   b  whose gas flow area is less then the surface area arc defined by the blade assembly  32  and the expansion chamber  24 . The blade assembly  32  is positioned with the nose cone  36  facing the inlet exhaust gas flow. The nose cone  36  is tapered at 45 degrees and is welded to the middle of the stationary propeller type blade assembly  32  that has been formed by water jetting stainless steel and bending the blades to the desired angle. In the preferred embodiment, the propeller comprises four blades with a rounded arcuate shape, each having about a 35 degree spiral twist. Alternatively, the blades have a turn of between about 20-60 degrees. There is no difference in performance if the blades are rotated clockwise or counterclockwise, as long as all blades are consistent with each other. In other embodiments, the propeller can have 2 to 8 blades. In another embodiment the propeller has 3 to 5 blades. In the preferred embodiment, the blades are relatively narrow. However, various blade widths may be utilized in the context of the invention.  
         [0022]     In  FIG. 4 , an arrow  42  at the input  20  of inlet tube  12  represents exhaust gas traveling in a substantially linear direction in that area. When the gas reaches stationary propeller type blade assembly  32  with a nose cone  36 , the exhaust gas is forced to spin in a vortex, as it passes through the expansion chamber  24 . The swirling effect forces the exhaust towards the tapered outlet tube  30  exit end. The spin-flow of the exhaust gasses is maintained to propel the gas out of the muffler through outlet tube  30  and leads to the atmosphere at distal end  40 , either directly or indirectly (e.g. via a tailpipe). The relative difference between the angled shape of airfoil surfaces of the nose cone  36  and the stationary propeller type blade assembly  32  (set at 45 and 35 degrees respectively in the preferred embodiment) assist in contouring the airflow. In an embodiment, outlet tube  30  has substantially the same interior diameter as inlet tube  12   b.  In another embodiment, the inlet tube  12   b  has a substantially smaller interior diameter than outlet tube  30 .  
         [0023]     Without being limited by any theory, it is believed that as turbulent exhaust gas enters the larger diameter of expansion chamber  24 , the gases are contoured and spun by a special set of vanes of the stationary propeller type blade assembly  32  with nose cone  36 . The result is a drop in pressure, which aids in scavenging the engine exhaust system. Engine exhaust gas flow velocity is kept high and unwanted backpressure is reduced. This facilitates the flow of the gasses through the expansion chamber and the outlet tube. The vortex effect creates a vacuum, which draws more gases from the exhaust source, increasing the exhaust throughput of the engine. It is found that the exemplary embodiments of the invention provide high performance propulsion exhaust chambers that increase horsepower, torque, and/or fuel efficiency for internal combustion engines, while maintaining the sound level of the engine within acceptable levels.  
         [0024]     Relative to similar standard mufflers that do not have the stationary propeller type blade assembly  32  with a nose cone  36 , it has been found that the horsepower of the engine can be increased from 13-19%, and fuel economy was increased by 10-14% in city driving, and from 14-18% in highway driving. Examples of vehicles that would benefit from the exhaust chamber system of the present invention include trucks, automobiles, riding lawn mowers, boats, snowmobiles, etc. Additionally, power machinery, or other equipment driven by internal combustion engines would also achieve performance improvements if equipped with the exhaust chamber system of the present invention.