Muffler having fluid swirling vanes

Abstract

A muffler for an internal combustion engine has a casing forming an expansion chamber therein. An inlet duct is connected to the casing and projects into the expansion chamber and discharges exhaust fluid into the expansion chamber. The casing tapers in an upstream direction to form a pocket for receiving reverse flow of the exhaust gases and to minimize reverse flow from flowing back into the inlet duct in an upstream direction. In the discharge end of the inlet duct are a set of primary vanes and a set of secondary vanes. The vanes are secured to the walls of the duct and extend radially toward the central area of the duct. The vanes are angled in order to deflect the exhaust fluid flow into a swirling movement as it is discharged into the expansion chamber and maintains that swirling movement while passing out of the casing through the outlet duct.

1 . A muffler for an internal combustion engine, comprising:
 a casing having an inlet port and an outlet port to allow an exhaust fluid stream to pass through said casing, said casing defining an expansion chamber therein;   an inlet duct connected to said inlet port and projecting into said chamber;   an outlet duct connected to said outlet port, said outlet duct in longitudinal alignment with said inlet duct, said outlet duct completely closed laterally and completely open at longitudinal ends thereof to allow the exhaust fluid stream to freely flow longitudinally therethrough;   a set of vanes mounted within said inlet duct, each vane of said set of vanes extending radially from a peripheral area of said inlet duct toward a central area thereof, said central area extending entire longitudinal length of said inlet duct, said central area entirely open to allow the exhaust fluid stream to freely flow longitudinally therethrough, said inlet duct and said outlet duct providing a longitudinally completely open longitudinal path therebetween and therethrough extending straight through entire longitudinal length of said casing for fluid to flow longitudinally straight and unobstructed through said casing.   
   
   
       2 . The device of  claim 1  wherein the said inlet duct extends into and terminates at a medial portion of said expansion chamber. 
   
   
       3 . The device of  claim 1  wherein said casing is convergently tapered in an upstream direction at said inlet port to partly define a pocket which is convergently tapered in an upstream direction, said pocket also defined by an outlet end of said inlet duct and constricted at said inlet port to trap reverse flowing fluid stream therein and thereby minimize reverse flow of the fluid stream. 
   
   
       4 . The device of  claim 1  wherein said set of vanes are angled in order to deflect fluid of a fluid stream passing through said casing and alongside said set of vanes. 
   
   
       5 . The device of  claim 1  wherein said set of vanes includes a plurality of primary vanes and a plurality of secondary vanes, said plurality of primary vanes secured at ends thereof to walls of said inlet duct, said plurality of secondary vanes secured at ends thereof to the walls of said inlet duct. 
   
   
       6 . The device of  claim 5  wherein each of said set of primary vanes and secondary vanes are oriented with bottom edge and lower edge thereof positioned in misalignment with top edge and upper edge thereof with reference to direction of fluid flow entering said casing through said inlet port and in a direction of the misalignment which is clockwise from a vantage point of fluid flow entering said casing so that each of said plurality of primary vanes and secondary vanes is at an angular orientation in order to impart a clockwise rotational movement to fluid flow passing thereagainst and thereby through said casing. 
   
   
       7 . The device of  claim 6  wherein said inlet duct has a discharge end edge, said top edge of all of said set of primary vanes flush with said discharge end edge. 
   
   
       8 . The device of  claim 5  wherein said plurality of primary vanes include main portions, lower medial portions and lower end portions which are angled horizontally relative to said main portions and in a clockwise direction from a vantage point of fluid flow entering said casing through said inlet port. 
   
   
       9 . The device of  claim 8  wherein each of said main portions are angled twelve degrees with reference to a plane which includes said top edge and the direction of fluid flow passing through said inlet port. 
   
   
       10 . The device of  claim 8  wherein each of said plurality of primary vanes have a bend line for said lower medial end portions, said bend line at a sixty degree angle relative to direction of fluid flow through said inlet port. 
   
   
       11 . The device of  claim 8  wherein said plurality of primary vanes have a bend line for said lower end portions, said bend line at a forty-five degree angle relative to direction of fluid flow through said inlet port. 
   
   
       12 . The device of  claim 11  wherein said lower end portions are angled twelve degrees relative to said lower medial portions in a horizontal direction and in a clockwise direction with reference to fluid flow passing through said inlet port. 
   
   
       13 . The device of  claim 5  wherein each of said plurality of primary vanes have an inner end portion and an outer end portion, said inner end portion longitudinally shorter than said outer end portion. 
   
   
       14 . The device of  claim 5  wherein said plurality of primary vanes and said plurality of secondary vanes are flat planar. 
   
   
       15 . The device of  claim 5  wherein said plurality of primary vanes include a set of pairs of primary vanes, each of said pairs interconnected adjacent the central area of said inlet duct so that said inlet duct is open at the central area for enhancing exhaust fluid flow through said inlet duct. 
   
   
       16 . The device of  claim 15  further including a set of interconnecting members for interconnecting said set of pairs of primary vanes at inner lateral end portions, said set of interconnecting members being laterally curved and longitudinally straight. 
   
   
       17 . The device of  claim 5  wherein said plurality of secondary vanes are of substantially shorter width than said plurality of primary vanes and of substantially shorter length than said housing and wherein said plurality of secondary vanes are positioned between said plurality of primary vanes. 
   
   
       18 . The device of  claim 1  wherein said set of vanes is positioned at a discharge end portion of said inlet duct. 
   
   
       19 . The device of  claim 1  wherein said casing, said inlet duct and said outlet duct are cylindrical. 
   
   
       20 . The device of  claim 19  wherein said casing has a diameter which is twice that of said inlet duct, and wherein said outlet duct has a diameter which is larger than said that of said inlet duct. 
   
   
       21 . The device of  claim 1  wherein said casing is convergently tapered in a downstream direction at the outlet port to facilitate fluid emission out of said casing and through said outlet port, said outlet port having a larger cross-sectional area than said inlet port to facilitate fluid emission out of said casing and through said outlet port.