Internal combustion engine with spherical rotary valve

Abstract

A cylinder head assembly has a substantially spherical body defining a central axis of rotation normal to the cylinder central axis and comprising a passageway there through to bring the combustion chamber into intermittent fluid communication with an exhaust duct for evacuating the burnt gases, said passageway comprising a 90 deg bend with: a first opening ( 31 ) to the exhaust duct substantially parallel to, preferably coaxial with the valve central axis of rotation, and a second opening to the combustion chamber, such that by rotation of the valve round its axis of rotation, said second opening can be intermittently brought into fluid communication with the combustion chamber.

1 . A cylinder head assembly ( 2 ) for an internal combustion engine having at least one cylinder housing containing a reciprocally movable piston along the central axis of revolution thereof, and a combustion chamber ( 3 ) on top of said piston, wherein said cylinder head assembly comprises a cavity ( 5 A) in fluid communication with said combustion chamber ( 3 ), and at least a first rotary valve ( 5 ) nested in said cavity ( 5 A), said valve,
 having a substantially spherical body defining a central axis of rotation normal to the cylinder central axis and   comprising a passageway therethrough to bring the combustion chamber into intermittent fluid communication with an exhaust duct for evacuating the burnt gases, said passageway comprising a 90 deg bend connecting:   a first opening ( 31 ) to the exhaust duct substantially parallel to, preferably coaxial with the valve central axis of rotation, to   a second opening ( 30 ), such that by rotation of the valve round its axis of rotation, said second opening ( 30 ) can be intermittently brought into fluid communication with the combustion chamber ( 3 ), and further comprising   a shaft ( 7 ) fixed to the valve and coaxial with the valve central axis of rotation and located opposite the exhaust duct ( 10 ), said shaft comprising connecting means to a drive for rotating the valve in correspondence with the operating strokes of the piston in the cylinder,   characterized in that,   the valve is rotatably mounted in cantilever within the cylinder head assembly through one or several bearings ( 8 ), all exclusively mounted around said shaft ( 7 ).   
     
     
         2 . Cylinder head assembly according to  claim 1 , wherein said first passageway opening ( 31 ) to the exhaust duct ( 10 ) is provided with a beak ( 9 ) jutting out of the sphere's wall and engaging into an inlet section of the exhaust duct ( 10 ) having a complementary geometry such that the burnt gases leaving the passageway's beak undergo a venturi effect preventing them from flowing backwards into the circumferential gap between the beak and the inlet section of the exhaust duct. 
     
     
         3 . Cylinder head assembly according to  claim 1 , wherein the rotary valve ( 5 ) sits on sealing means ( 12 ) to seal the passage between the combustion chamber and the rotary valve, said sealing means comprising a Belleville type washer. 
     
     
         4 . Cylinder head assembly according to  claim 1 , wherein the rotary valve comprises sealing means ( 13 ) to seal the passage between the shaft ( 7 ) and the cavity ( 5 A), said sealing means preferably comprising a Belleville type washer. 
     
     
         5 . Cylinder head assembly according to  claim 1 , wherein the rotary valve ( 5 ) is mounted within the cylinder head assembly through at least two bearings ( 8 ). 
     
     
         6 . Cylinder head assembly according to  claim 1 , wherein the second opening ( 30 ) to the combustion chamber is larger than the first opening ( 31 ) to the exhaust duct ( 10 ), the second opening ( 30 ) being preferably elongated in the direction of rotation, most preferably, the second opening ( 30 ) being offset with respect to the valve central axis of rotation. 
     
     
         7 . Cylinder head assembly according to  claim 1 , further comprising an second rotary valve ( 25 ) which can be brought in intermittent fluid communication with said combustion chamber ( 3 ), said valve ( 25 ) having a substantially spherical body defining a central axis of rotation parallel to or coaxial with the central axis of rotation of the first rotary valve ( 5 ), and comprising:
 a passageway therethrough suitable for bringing in fluid communication a fuel & air injection line ( 20 ) with the combustion chamber ( 3 ), for injecting fresh fuel & air therein, said passageway comprising a 90 deg bend with:   a first opening ( 31 A) to the fuel & air injection line ( 20 ), wherein the passageway is substantially parallel to, preferably coaxial with the valve central axis of rotation, and   a second opening ( 30 A), such that by rotation of the valve round its axis of rotation, said second opening can be intermittently brought into fluid communication with the combustion chamber,   and wherein the first and second rotary valves ( 5 ,  25 ) are so mounted that upon rotation round their respective axis of rotation, the facing of their respective second openings ( 30 ,  30 A) with the combustion chamber is off phase.   
     
     
         8 . Internal combustion engine comprising at least one cylinder housing containing a reciprocally movable piston along the central axis of revolution thereof, and a combustion chamber on the top of said cylinder, wherein said combustion chamber is in fluid communication with a cylinder head assembly for an internal combustion engine having at least one cylinder housing containing a reciprocally movable piston along the central axis of revolution thereof, and a combustion chamber ( 3 ) on top of said piston, wherein said cylinder head assembly comprises a cavity ( 5 A) in fluid communication with said combustion chamber ( 3 ), and at least a first rotary valve ( 5 ) nested in said cavity ( 5 A), said valve,
 having a substantially spherical body defining a central axis of rotation normal to the cylinder central axis and   comprising a passageway therethrough to bring the combustion chamber into intermittent fluid communication with an exhaust duct for evacuating the burnt gases, said passageway comprising a 90 deg bend connecting:   a first opening ( 31 ) to the exhaust duct substantially parallel to, preferably coaxial with the valve central axis of rotation, to   a second opening ( 30 ), such that by rotation of the valve round its axis of rotation, said second opening ( 30 ) can be intermittently brought into fluid communication with the combustion chamber ( 3 ), and further comprising   a shaft ( 7 ) fixed to the valve and coaxial with the valve central axis of rotation and located opposite the exhaust duct ( 10 ), said shaft comprising connecting means to a drive for rotating the valve in correspondence with the operating strokes of the piston in the cylinder,   characterized in that,   the valve is rotatably mounted in cantilever within the cylinder head assembly through one or several bearings ( 8 ), all exclusively mounted around said shaft ( 7 ).   
     
     
         9 . Internal combustion engine according to  claim 8 , wherein it is a two stroke engine. 
     
     
         10 . Internal combustion engine according to  claim 9 , wherein several transfer ports ( 15 ), distributed around the whole circumference of the cylinder above the piston head at its lowest position in the cylinder, are in fluid communication with transfer ducts ( 14 ), which have a tangential component with respect to the cylinder circumference such as to impart a spinning movement to the combustion fluid injected into the cylinder. 
     
     
         11 . Internal combustion engine according to  claim 9 , wherein transfer ports ( 15 ), distributed round the circumference of the cylinder and through which transfer ducts ( 14 ) are in fluid communication with the combustion chamber ( 3 ), extend over not more than a quarter of the total height of the combustion chamber when the piston is at its lowest position. 
     
     
         12 . Internal combustion engine according to any of  claims 9  to  11 , comprising at least five transfer ducts, preferably at least six transfer ducts ( 14 ) in fluid communication with the corresponding transfer ports. 
     
     
         13 . Internal combustion engine according to  claim 8 , wherein it is a four stroke engine. 
     
     
         14 . Internal combustion engine according to  claim 13 , comprising a cylinder head assembly which comprises a second rotary valve ( 25 ) which can be brought in intermittent fluid communication with said combustion chamber ( 3 ), said valve ( 25 ) having a substantially spherical body defining a central axis of rotation parallel to or coaxial with the central axis of rotation of the first rotary valve ( 5 ), and comprising.
 a passageway therethrough suitable for bringing in fluid communication a fuel & air injection line ( 20 ) with the combustion chamber ( 3 ), for injecting fresh fuel & air therein, said passageway comprising a 90 deg bend with:   a first opening ( 31 A) to the fuel & air injection line ( 20 ), wherein the passageway is substantially parallel to, preferably coaxial with the valve central axis of rotation, and   a second opening ( 30 A), such that by rotation of the valve round its axis of rotation, said second opening can be intermittently brought into fluid communication with the combustion chamber,   and wherein the first and second rotary valves ( 5 ,  25 ) are so mounted that upon rotation round their respective axis of rotation, the facing of their respective second openings ( 30 ,  30 A) with the combustion chamber is off phase.