Abstract:
An internal combustion engine utilizing an additional vapor expansion piston/cylinder to capture traditionally rejected energy. Hot combustion gases from the combustion process are used to power an additional vapor expansion cycle in a separate cylinder from the combustion cycle. Comprised of at least two pistons/cylinders (one fuel combustion and one vapor expansion) diametrically opposed; where the reciprocal motion of the pistons is transferred to the output shaft via a multiple-lobed rotor assembly.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/881,923, filed Sep. 24, 2013. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Since the introduction of the internal combustion engine many improvements have been introduced to increase its efficiency. However, despite its long evolvement, modern day engines are typically only capable of 25% to 40% thermal efficiency, meaning 60% to 75% of the energy of the fuel is rejected. Many attempts have been made to capture the wasted energy and convert it into useful work. Previous efforts have included using additional cycles (within the same cylinder) which use hot combustion gases to convert water/fluid into a vapor; which expand and impart force on the piston producing work. The addition of vapor expansion cycles within the same cylinder introduces lubrication difficulty between the piston and cylinder surfaces, as well as requiring non-standard camshaft designs for valve operation. 
         [0003]    Another area of inefficiency is how the piston transfers reciprocal motion to the crankshaft, via the connecting rod, where it is converted to rotational output. As the piston acts on the connecting rod and crankshaft at various angles there is a reduction in efficiency depending on the angle. Alternative designs have been explored to minimize the crank angles and achieve a perpendicular relationship. However, a flaw of the linear engine design is the lack of limiting stops for the piston travel path; as well as a means for starting the engine, without additional complex systems. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention comprises an internal combustion engine that consists of at least one fuel combustion piston/cylinder and at least one vapor expansion piston/cylinder that are connected to an individual respective linear connecting rod and act upon a central rotating multiple-lobed rotor assembly. The engine utilizes linear bearing supports, roller bearings, a counter rotating mid-rotor, and springs (or grooved outer rotors) to significantly reduce piston/cylinder side wear and crank angle inefficiencies. The exhausted combustion gases are introduced into the vapor expansion cylinder and are used to provide thermal energy for the vapor expansion cycle. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1 .  FIG. 1  illustrates a simplified arrangement of the present invention. 
           [0006]      FIG. 2 .  FIG. 2  (Section of  FIG. 1 ) shows the orientation of the piston/cylinders, compression springs, linear bearing supports, roller bearings, and rotor assembly. 
           [0007]      FIG. 3 .  FIG. 3  depicts the arrangement of the outer rotors, middle rotor, and output shaft. 
           [0008]      FIG. 4 .  FIG. 4  illustrates the arrangement of the rotor assembly, counter rotation shaft, auxiliary shaft, and associated gearing. 
           [0009]      FIG. 5 .  FIG. 5  shows an isometric view of the grooved outer rotors, middle rotor, connecting rod and output shaft. 
           [0010]      FIG. 6 .  FIG. 6  shows a front view of the grooved outer rotors, middle rotor, connecting rod and output shaft. 
           [0011]      FIG. 7 .  FIG. 7  depicts an arrangement of the present invention where multiple cylinder units are arranged lineally about a common output shaft. 
           [0012]      FIG. 8 .  FIG. 8  depicts an arrangement of the present invention where multiple cylinder units are arranged radial about a common rotor assembly and output shaft. 
           [0013]      FIG. 9 .  FIG. 9  illustrates and alternative mode of transferring the piston reciprocal motion to rotary motion via a conventional connecting rod and crank shaft. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0014]      FIG. 1  illustrates a simplified arrangement of the present invention. The gas combustion phase is intended to operate on a cycle similar to the Otto, Diesel, or similar cycle. This description will entail the Otto cycle; however, let it be known that the Diesel cycle or similar is a suitable alternative. The present invention is an internal combustion engine comprised of at least one fuel combustion piston/cylinder ( 1  &amp;  2 ) and at least one vapor expansion piston/cylinder ( 8  &amp;  9 ) connected to their respectful connecting rod assembly, which operate on a linear path. The pistons travel is limited by the travel path of the compression spring ( 32 ) and the rotation of the multiple-lobed rotors ( 35 ,  36 , &amp;  37 ). The arrangement of the engine components are contained in a suitable housing that offers both structural support for the components and shafting as well as the appropriate interface for fittings/couplings of the various medium conduits, both rigid and flexible. 
         [0015]    First discussing the fuel combustion process, the air/fuel mixture ( 16 ) is introduced into the fuel combustion cylinder ( 1 ) through the open fuel combustion intake valve ( 5 ) as the fuel combustion piston ( 2 ) travels away from the fuel combustion intake valve, as acted upon by the compression spring ( 32 ), creating a pressure difference. The fuel combustion exhaust valve ( 6 ) remains closed during this operation. Once the fuel combustion piston ( 2 ) nears the end of the intake stroke, the fuel combustion intake valve ( 5 ) moves to the closed position, as it is actuated by a camshaft. The fuel combustion piston ( 2 ), reaches the lower limit of the intake stroke as dictated by the travel of the outer multiple-lobed rotor ( 35 ), outer multiple-lobed rotor ( 36 ), and middle multiple-lobed rotor ( 37 ). As the fuel combustion piston travels toward the fuel combustion intake valve ( 5 ) and fuel combustion exhaust valve ( 6 ), it compresses the air/fuel mixture ( 16 ) until it nears the top of the compression stroke where the air/fuel mixture ( 16 ) is ignited by the spark plug ( 7 ). Both fuel combustion valves ( 5  &amp;  6 ) remain closed. The rapidly expanding combustion gas forces the fuel combustion piston ( 2 ) away from the spark plug ( 7 ). The energy is transferred to the connecting rod ( 30 ), rotor roller bearing ( 33 ), and finally to the multiple-lobed rotors ( 35 ,  36 , &amp;  37 ), where the reciprocal energy is converted to rotary motion. 
         [0016]    As the fuel combustion piston ( 2 ) approaches the lower limit of the expansion stroke the fuel combustion exhaust valve ( 6 ) opens to allow the hot combustion exhaust ( 17 ) to escape. The fuel combustion piston ( 2 ) travels toward the spark plug ( 7 ) removing the combustion exhaust ( 17 ) from the fuel combustion cylinder ( 1 ). Next discussing the vapor expansion process, on the following stroke, the vapor expansion intake valve ( 10 ) opens and the vapor expansion piston ( 9 ) travels away from the vapor expansion intake valve ( 10 ) filling the vapor expansion cylinder ( 8 ) with the hot combustion exhaust ( 17 ). The fuel combustion exhaust valve ( 6 ) is connected to the vapor expansion intake valve ( 10 ) via rigid conduit that is insulated to minimize heat loss. Additionally, the vapor expansion piston ( 9 ) is connected to a connecting rod ( 30 ) which is acts upon the multiple-lobed rotors ( 35 ,  36 , &amp;  37 ). 
         [0017]    As the vapor expansion piston ( 9 ) nears the lower limit of the intake stroke (as acted upon by the compression spring ( 32 )), the vapor expansion intake valve ( 10 ) moves to the closed position as actuated by a camshaft. The vapor expansion exhaust valve ( 11 ) remains closed during this operation. As the vapor expansion piston ( 9 ) travels toward the vapor expansion intake valve ( 10 ) and vapor expansion exhaust valve ( 11 ) it compresses the combustion exhaust ( 17 ) until it nears the top of the compression stroke where the compressed fluid ( 22 ), i.e. water or similar mixture thereof, after being pressurized by the high pressure pump ( 12 ), is injected into the vapor expansion cylinder ( 8 ) by the water injector ( 13 ). Both vapor expansion valves ( 10  &amp;  11 ) remain closed. The rapidly expanding vapor (steam) forces the vapor expansion piston ( 9 ) away from the water injector ( 13 ). The energy is transferred to the connecting rod ( 30 ), rotor roller bearing ( 33 ), and finally to the multiple-lobed rotors ( 35 ,  36 , &amp;  37 ), where the reciprocal energy is converted to rotary motion. 
         [0018]    As the vapor expansion piston ( 9 ) approaches the lower limit of the expansion stroke the vapor expansion exhaust valve ( 11 ) opens to allow the exhaust ( 26 ) to escape. The vapor expansion piston ( 9 ) travels toward the water injector ( 13 ) removing the exhaust ( 26 ) from the vapor expansion cylinder ( 8 ). The exhaust ( 26 ) travels through rigid conduit to the condenser ( 18 ) where it is cooled and allowed to condense. The remaining exhaust ( 26 ) is emitted from the system. 
         [0019]    The cooled condensate ( 19 ) is directed to the condensate pump ( 20 ) where it is forced through the filter ( 21 ) to remove particulates. The purified condensate ( 19 ) is then united with the compressed fluid ( 22 ) returning from the radiator. The compressed fluid ( 22 ) is then directed to the compressed fluid inlet ( 23 ) via rigid and/or flexible conduit. The compressed fluid ( 22 ) fills the water jacket ( 24 ) surrounding the fuel combustion cylinder and 1) removes the excess thermal energy of the combustion process and stores the thermal energy in the compressed fluid ( 22 ); 2) preheats the compressed fluid ( 22 ) before it is injected into the vapor expansion cylinder ( 8 ). The compressed fluid ( 22 ) is then directed toward the high pressure pump ( 12 ) via rigid and/or flexible conduit. The compressed fluid ( 22 ) that cannot be consumed by the vapor expansion process is diverted to a radiator where subsequent cooling occurs. 
         [0020]    Let it be known that it may not be practical for the compressed fluid ( 22 ) to circulate the water jacket ( 24 ) for practical applications. In this situation, it may be reasonable to include a subsequent heat exchanger between a secondary medium (coolant) after it exits the water jacket ( 24 ) (at the compressed fluid outlet ( 25 )) and the compressed fluid ( 22 ) before it enters the high pressure pump ( 12 ). 
         [0021]    As the fuel combustion piston ( 2 ) and the vapor expansion piston ( 9 ) oscillate in their respective cylinders ( 1  &amp;  8 ) the energy is converted to rotary motion via the outer multiple-lobed rotor ( 35 ), outer multiple-lobed rotor ( 36 ), and middle multiple-lobed rotor ( 37 ). The middle multiple-lobed rotor ( 37 ) is rotating at an equal rate, but opposite direction to the outer multiple-lobed rotors ( 35  &amp;  36 ). All multiple-lobed rotors provide positive rotational force to the output shaft ( 34 ). The middle multiple-lobed rotor does not directly transfer energy to the output shaft ( 34 ), but rather is designed to “free wheel” on the output shaft ( 34 ), and transfer energy via the middle rotor gear ( 40 ), auxiliary shaft gear ( 44 ), auxiliary shaft ( 39 ), counter rotation gears ( 42  &amp;  43 ), counter rotation shaft ( 38 ), and output shaft gear ( 41 ) where the energy is transferred to the output shaft ( 34 ). The counter rotational middle multiple-lobed rotor is required to produce balanced energy transition between the connecting rod ( 30 ) and multiple-lobed rotors ( 35 ,  36 , &amp;  37 ), where it cancels the force of the outer multiple-lobed rotors ( 35  &amp;  36 ) and allows the sum of the side forces acting on the rotor roller bearing ( 33 ) to equal zero. The linear bearing ( 31 ) is used to provide stability to the connecting rod ( 30 ). The compression spring ( 32 ) is used to provide constant contact between the rotor roller bearings ( 33 ) and the multiple-lobed rotors ( 35 ,  36 , &amp;  37 ). The compression spring ( 32 ) is also used to provide energy to the pistons ( 2  &amp;  9 ) via the connecting rods ( 30 ) to produce the “intake” strokes. However as the cycle speed of the engine is increased it may not be practical to rely solely on energy stored in a mechanical spring to provide the means for an intake strokes. Therefore, a grooved outer rotor ( 45  &amp;  46 ) may need to be utilized (or combination of springs and grooved rotors) to provide a limiting boundary to return the pistons ( 2  &amp;  9 ) via the connecting rods ( 30 ) to perform the “intake” strokes. Alternatively, reciprocal motion from the pistons may be converted to rotary motion via a conventional connecting rod and crankshaft ( 47  &amp;  48 ).