Gaseous fueled two-stroke engine

Abstract

An engine according to various embodiments generates reduced emissions.

1 . A gaseous fueled two-stroke engine  100  having a carburetor for gaseous fuel  124  with an oil injection pump  138  driven by a crankshaft  106  with an LPG or Butane fuel tank attached to the engine and a separate oil tank  140  and having a catalytic muffler  128  to reduce engine out unburned emissions from a gaseous fuel, and unburned emissions generated from oil, where the exhaust total emissions from muffler outlet are less than 50 gm/kw-hr. 
     
     
         2 . The engine as claimed in  1 , having an intake port  136  and a temperature sensor to sense an ambient temperature at the intake port and to cut off ignition when the difference between the ambient temperature and an engine temperature is above a predetermined level. 
     
     
         3 . The engine as claimed in  1 , having an oil pressure sensor to cut off ignition when an oil pressure in the oil outlet pressure is below a predetermined level. 
     
     
         4 . The engine as claimed in  1 , having an oil level sensor in the oil tank  140  to cut off ignition when an oil level in the oil tank  140  is below a predetermined level. 
     
     
         5 . The engine as claimed in  claim 1  having a catalytic muffler  128  for reducing exhaust emissions, in which the engine is a gaseous fueled small engine less than 100 cc. 
     
     
         6 . The engine according to  claim 2  in which the muffler  128  includes a catalyst element  130  to reduce unburned propane fuel and unburned hydrocarbons generated from oil. 
     
     
         7 . The engine according to  claim 2  in which the muffler  128  includes a catalyst element  130  to treat the unburned butane fuel. 
     
     
         8 . The engine according to  claim 2  in which the muffler  128  includes a catalyst element  130  to treat unburned hydrocarbon. 
     
     
         9 . The engine according to  claim 2  in which the muffler  128  includes a catalyst element  130  to reduce NOx, in which the engine is a lean burn gaseous fueled two-stroke engine. 
     
     
         10 . The engine according to  claim 2  in which the muffler  128  includes a catalyst element  130  to oxidize unburned hydrocarbon in exhaust gas. 
     
     
         11 . The engine as claimed in  claim 2  having Propane (LPG) as a fuel. 
     
     
         12 . The engine as claimed in  claim 2  having Butane as a fuel. 
     
     
         13 . The engine as claimed in  claim 1 , in which the oil injection pump is a variable rate oil injection pump injecting substantially less oil per hour at idle speed than the oil injection rate at maximum speed. 
     
     
         14 . The engine as claimed in  claim 1 , in which the oil injection pump is a speed governed oil injection pump. 
     
     
         15 . The engine as claimed in  claim 1 , in which the oil injection pump is a throttle piston governed oil injection pump. 
     
     
         16 . The engine as claimed in  claim 1 , further including an electronic temperature sensor. 
     
     
         17 . The engine as claimed in  claim 1 , further including a bimetal temperature sensor to cut off the engine in the event that oil fails to be delivered to the engine, in order to protect against engine failure in such circumstances. 
     
     
         18 . The engine as claimed in  claim 1  having an oil feed system having all attitude oil inlet  148  and shape of an all attitude oil tank  140 . 
     
     
         19 . The engine as claimed in  1 , in which the engine is a stratified two-stroke engine. 
     
     
         20 . The engine of  claim 14  in which the oil feed system includes an oil feed line  148  that is rotatably mounted in the oil tank and has flexible oil line. 
     
     
         21 . A gaseous fueled two-stroke engine  100  having a gaseous carburetor  124  with an oil injection pump  138  driven by a crankshaft  106  with an LPG or Butane fuel tank attached to the engine and a separate oil tank  140  shaped such as to access oil at all engine attitudes and having a catalytic muffler  128  to treat the exhaust gas where the exhaust emissions are no more than 50 gm/kw-hr and the oil consumption is between 1.2 to 6% of fuel consumption rate. 
     
     
         22 . A gaseous fueled two-stroke engine  100  having a carburetor for gaseous fuel  124  with an variable rate oil injection pump  138  driven by a crankshaft  106  with an LPG or Butane fuel tank attached to the engine and a separate oil tank  140  and having a catalytic muffler  128  to reduce high engine out emissions to exhaust gas where the exhaust emissions are less than 50 gm/kw-hr and the gaseous fuel is substantially free of pre-mixed oil. 
     
     
         23 . A gaseous fueled two-stroke engine  100  having a carburetor for gaseous fuel  124  with an oil injection pump with a gaseous fueled tank attached to the engine and a separate oil tank  140  shaped such as to access oil at all engine attitudes and having a catalytic muffler  128  to treat the exhaust gas where the exhaust emissions are less than 50 gm/kw-hr and the gaseous fuel is substantially free of pre-mixed oil.