Exhaust system of a marine vessel

Abstract

An exhaust system for a marine propulsion device is configured to dispose two exhaust conduits in generally concentric overlapping relation with each other in order to minimize the potential cross sectional area of a leak path in the event that a seal fails. One of the exhaust conduits extends through a transom or other surface of a marine vessel and another exhaust conduit conducts exhaust gas from an engine to the exhaust conduit extending through the surface of the marine vessel.

1 . A marine vessel exhaust system, comprising:
 a first exhaust conduit;   a second exhaust conduit, an end portion of said second exhaust conduit being disposed within an end portion of said first exhaust conduit; and   a seal disposed between said end portion of said second exhaust conduit and said end portion of said first exhaust conduit.   
     
     
         2 . The exhaust system of  claim 1 , wherein:
 said seal is disposed between an outer surface of said end portion of said second exhaust conduit and an inner surface of end portion of said first exhaust conduit.   
     
     
         3 . The exhaust system of  claim 2 , wherein:
 said seal has a radial inward extension deformed along a taper as it extends from said inner surface of said end portion of said first exhaust conduit to said outer surface of said end portion of said second exhaust conduit.   
     
     
         4 . The exhaust system of  claim 2 , wherein:
 said seal extends from said inner surface of said end portion of said first exhaust conduit to said outer surface of said end portion of said second exhaust conduit such that increasing exhaust pressure in said exhaust conduits increases sealing pressure applied by said seal between said exhaust conduits.   
     
     
         5 . The exhaust system of  claim 2 , wherein:
 said end portion of said second exhaust conduit and said end portion of said first exhaust conduit are generally concentric in axially overlapped relation,   and comprising a ridge formed on one of said exhaust conduits facilitating clamping of said exhaust conduits together and limiting and defining axial travel therebetween.   
     
     
         6 . The exhaust system of  claim 2 , further comprising:
 an engine connected in fluid communication with said first and second exhaust conduits; and   a surface of a marine vessel, said first and second exhaust conduits being configured to conduct a stream of exhaust from said engine through said surface;   wherein said seal has a radially inward extension deformed along a taper as it extends from said inner surface of said end portion of said first exhaust conduit to said outer surface of said end portion of said second exhaust conduit;   said seal extends along said taper such that increasing exhaust pressure in said exhaust conduits applied to said taper increases sealing pressure applied by said seal between said exhaust conduits.   
     
     
         7 . The exhaust system of  claim 6 , wherein:
 said surface is a transom of said marine vessel.   
     
     
         8 . The exhaust system of  claim 6 , further comprising:
 a marine propulsion drive connected in torque transmitting relation with a crankshaft of said engine.   
     
     
         9 . The exhaust system of  claim 2 , wherein:
 said end portion of said second exhaust conduit and said end portion of said first exhaust conduit are generally concentric in axially overlapped relation,   and comprising axial retention clamp rings providing axial retention force retaining said exhaust conduits in axially clamped relation.   
     
     
         10 . The exhaust system of  claim 9  comprising one or more axial biasing members providing axially biased clamping force between said exhaust conduits. 
     
     
         11 . A marine vessel exhaust system, comprising:
 a first exhaust conduit;   a second exhaust conduit, an end portion of said second exhaust conduit being disposed within an end portion of said first exhaust conduit;   a seal disposed between said end portion of said second exhaust conduit and said end portion of said first exhaust conduit;   an engine connected in fluid communication with said first and second exhaust conduits; and   a surface of a marine vessel, said first and second exhaust conduits being configured to conduct a stream of exhaust gas from said engine through said surface.   
     
     
         12 . The exhaust system of  claim 11 , wherein:
 said seal is disposed between an outer surface of said end portion of said second exhaust conduit and an inner surface of end portion of said first exhaust conduit;   said seal has a radially inward extension deformed along a taper as it extends from said inner surface of said end portion of said first exhaust conduit to said outer surface of said end portion of said second exhaust conduit;   said seal extends along said taper such that said taper is exposed to increasing exhaust pressure in said exhaust conduits such that said increasing exhaust pressure applied against said taper increases sealing pressure applied by said seal between said exhaust conduits.   
     
     
         13 . The exhaust system of  claim 12 , further comprising:
 a marine propulsion drive connected in torque transmitting relation with a crankshaft of said engine.   
     
     
         14 . The exhaust system of  claim 13 , wherein:
 said end portion of said second exhaust conduit and said end portion of said first exhaust conduit are generally concentric in axially overlapped relation;   and comprising a ridge formed on one of said exhaust conduits facilitating clamping of said exhaust conduits together and limiting and defining axial travel therebetween;   and comprising axial retention clamp rings providing axial retention force retaining said exhaust conduits in axially clamped relation;   and comprising one or more axial biasing members providing axially biased clamping force between said exhaust conduits.   
     
     
         15 . The exhaust system of  claim 14 , wherein:
 said seal is an elastomeric lip seal.   
     
     
         16 . The exhaust system of  claim 14 , wherein:
 said surface is a transom of said marine vessel.   
     
     
         17 . The exhaust system of  claim 16 , wherein:
 said marine propulsion drive is a stemdrive unit and said stream of exhaust gas is conducted through said stemdrive unit.   
     
     
         18 . A marine vessel exhaust system, comprising:
 a first exhaust conduit;   a second exhaust conduit, an end portion of said second exhaust conduit being disposed within an end portion of said first exhaust conduit;   a seal disposed between an outer surface of said end portion of said second exhaust conduit and an inner surface of end portion of said first exhaust conduit, said end portion of said second exhaust conduit and said end portion of said first exhaust conduit being generally concentric in axially overlapped relation;   an engine connected in fluid communication with said first and second exhaust conduits; and   a surface of a marine vessel, said first and second exhaust conduits being configured to conduct a stream of exhaust gas from said engine through said surface, wherein:   said seal has a radially inward extension deformed along a taper as it extends from said inner surface of said end portion of said first exhaust conduit to said outer surface of said end portion of said second exhaust conduit;   said seal extends along said taper such that said taper is exposed to increasing exhaust pressure in said exhaust conduits which increasing exhaust pressure applied to said taper increases sealing pressure applied by said seal between said exhaust conduits;   and comprising a ridge formed on one or said exhaust conduits facilitating clamping of said exhaust conduits together and limiting and defining axial travel therebetween;   and comprising axial retention clamp rings provides axial retention force retaining said exhaust conduits in axially clamped relation;   and comprising one or more axial biasing members providing axially biased clamping force between said exhaust conduits.   
     
     
         19 . The exhaust system of  claim 18 , further comprising:
 a marine propulsion drive connected in torque transmitting relation with a crankshaft of said engine.   
     
     
         20 . The exhaust system of  claim 19 , wherein:
 said surface is a transom of said marine vessel, said marine propulsion drive is a stemdrive unit and said stream of exhaust gas is conducted through said stemdrive unit.