Patent Publication Number: US-2004050356-A1

Title: Stotler radial rotary piston engine

Description:
BACKGROUND OF THE INVENTION  
       [0001] Commercially viable combustion engines have included four-cycle and two-cycle reciprocating piston engines, turbine engines, and the F. Wankel Rotary Engine. The object of this invention is to improve upon these existing technologies by combining some of their features along with some unique features. The four-cycle reciprocating piston engine has emerged as the most practical for the use in automobiles, motorcycles, and heavy equipment. The efficiency, durability, and manufacturability of the seal created by the piston rings upon the cylinder wall is one of the advantages of this design and this feature has been incorporated into this new design. However the valve train has been a limiting factor in the performance, economy, and reliability of the common reciprocating piston engine. The Wankel Rotary Engine, U.S. Pat. No. 2,988,065 in 1961 was successful in eliminating the need for a complex and expensive valve train by replacing the function of the valves with the motion of the rotor. The function of the valve train will be accomplished in this design by the rotary valve hub. In existing patents the concept of a rotary valve was added to an in line piston engine by J. U. Qattan, U.S. Pat. No. 6,443,110 in 2002 and a recent radial engine design was patented by S. Cunningham U.S. Pat. No. 6,443,047 in 2002.  
       SUMMARY OF THE INVENTION  
       [0002] The present invention comprises an internal combustion engine with at least one piston that rotates in relation to a hub that acts as a rotary valve. Multiple pistons, eight in this example, are arranged radially around the central hub and compress inward toward the hub. The hub acts as a single rotary valve that services all the pistons that revolve around it. The rotary valve hub includes passageways to provide for fuel/air intake, exhaust, and coolant as well as an ignition devise. The pistons are actuated by separate gear driven crankshafts that are driven by a gear affixed to the hub. The crankshaft gear having one half the radius of the hub gear, will rotate twice as it circles the hub, providing four cycles of piston motion. As the hub rotates once in relation to the piston cylinder it opens to provide a fuel air mixture during the intake stoke of the piston, seals the cylinder for the compression stoke, ignites combustion, remains sealed for the power stroke and opens the cylinder to allow gasses to escape during the exhaust stroke. 
     
    
    
     BRIEF DESCIPTIONS OF THE DRAWINGS  
     [0003] The accompanying drawings illustrate the invention and in such drawings:  
     [0004]FIG. 1 is a partial cross sectional view perpendicular to the axis of rotation of the engine of the present invention with eight cylinders.  
     [0005]FIG. 2 is a perpendicular cross sectional view of FIG. 1 through line I.  
    
    
     DETAILED DESCRIPTION OF THE NVENTION  
     [0006]FIG. 1 is a partial cross sectional view of the engine of the present invention with eight cylinders. This view is perpendicular to the engine&#39;s axis of rotation and this view is centered though the ring of cylinders. This view is of the internal mechanism of the engine for which the current invention is concerned. The external housing of the engine is not shown. Piston  1   a  is shown in the intake cycle. Piston  1   b  is shown in the compression cycle. Piston  1   c  is shown at the point of ignition. Piston  1   d  is shown in the power cycle. Piston  1   e  is shown in the exhaust cycle.  
     [0007] The engine block  2  unites all cylinders in a ring around the central rotary valve hub  3 . The piston rings  4  form a seal between the piston and the cylinder wall  5 . The hub gear  6   a  and the crank gear  7   a  are shown in this drawing but exist in a different but parallel plane and thus are depicted by a dashed line. The hub gear is affixed to and maintains its orientation with the hub. The crank gear mounts to the cylinder block by means of a crankshaft bearing  8 . The crankshaft meets with the actual plane of the drawing where it connects with the connecting rod  10   a  at connecting rod bearing  9 . The connecting rod connects to the piston with the piston bearing  11 . The engine block may be mounted using a bolt  19  at this location, as there is no interference with the crank gears.  
     [0008] The rotary valve hub  3  acts as single rotary valve that services all the pistons that revolve around it. A seal  12   a  is formed between the hub and cylinder block. The simple cylindrical nature of this seal will allow for its manufacture to tight tolerances and thus efficiently sealing the combustion chamber  13 . The rotary valve hub includes: a passageway  14   a  for a fuel/air mixture to enter the cylinders during the intake stoke, an ignition device  15 , a passageway  16   a  for exhaust gasses to exit the cylinders during the exhaust stoke, and passageways for coolant  17   a.    
     [0009]FIG. 2 is a perpendicular cross sectional view of FIG. 1 through broken line I and along the axis of rotation. The cylinder block  2 , piston  1   f , crankshaft  18 , and connecting rod  10   b  are shown as the piston reaches its furthest point from the hub after intake. This cross section shows the hub gear  6   b  and crank gear  7   b  in true relation to the cylinder block assembly. The passageways within the hub are simplified for the purpose of this explanation and would not appear along the cross sectional plane as shown and therefore are drawn with a dashed line. The axial length of the hub has been exaggerated and the passageways simplified for the sake of illustration. The exhaust passageway  16   b  would continue on to the exhaust system. The coolant exit passageway  17   b  and coolant entrance pathway  17   c  would continue to the radiator. The fuel/air passageway  14   b  would continue to a carburetor or fuel injection system.  
     [0010] For the purpose of this description a stationary hub with rotating cylinder block assembly will be used. However, this invention can be made to function with a rotating hub and stationary cylinder block or a rotating hub and counter rotating cylinder block. In all cases the hub gear has a circumference twice that of the crank gear and thus the crankshaft rotates twice as the cylinder block rotates once relative to the hub. Two rotations of the crankshaft results in four stokes of the piston and therefore providing for the four engine cycles.  
     [0011] The rotary valve hub design allows the ignition devise to be either a spark plug or a glow plug. The ignition wire and a passageway to access the ignition devise would be located within the hub. The location of the intake passageway, exhaust passageway, and ignition devise within the hub can be changed with respect to the cylinder cycles thereby changing their timing with the cycles. In this way the engine can be tuned to produce a variety of performance, fuel efficiency, and exhaust emissions goals. This can also be achieved during engine operation by including mechanisms within the hub that change the dimensions and or locations of the passageways or ignition devise within the hub. In addition, a mechanism that rotates the gear hub with respect to the hub would have a similar tuning effect by advancing the cylinder cycles.  
     [0012] The gear driven crankshaft system as detailed in the drawings may be replaced if desired by a cam system such as described by R. L. Russell U.S. Pat. No. 5,636,599 in 1997. This would allow for further tuning of the four engine cycles and give the engine additional flexibility to achieve various performance and emissions goals.  
     [0013] Engines of the type of the present invention may be made with up to 18 cylinders arranged radially around the hub and aligned along the same plane using the gear driven crankshaft design. The number of cylinders within a single ring is limited by the clearance requirements of the crank gears. If a greater power density is desired, the engine of the type of the present invention may be made with multiple rings of radially aligned pistons therefore providing for an unlimited number of pistons and configurations.  
     [0014] Passageways for coolant have only been shown in the drawings within the hub. The location and number of these passageways could be changed to achieve different cooling effects. In addition coolant passageways could be added to the cylinder block and enter or exit the block near the mounting bolts  19 . This is required to avoid interference with the crank gears. Similarly passageways for lubricants can be added to the hub and cylinder block to satisfy various lubrication and cooling needs.  
     [0015] The cylindrical shape of the seal between the hub and the cylinder block was intentional as cylindrical surfaces can be efficiently manufactured to tight tolerances. It is intended that a seal between the hub and the cylinder block surfaces can be made that is durable and will allow for efficient operation of the engine. If a tighter seal is required a sleeve can be added as a cylinder liner that is spring loaded to form a tight seal with the hub. In addition, bearings could be added between the hub and the cylinder block to increase the efficiency of this seal and to reduce friction.  
     [0016] Several embodiments of the present invention have been described in detail; however, various modifications may be made without departing from the scope and spirit of the invention. Accordingly the present invention is not to be limited, except as by the following claims.