Abstract:
A head assembly and valve-less internal combustion engine are disclosed. The head assembly includes a head having a first port extending through the head and a surface defining a portion of a combustion chamber in fluid communication with the first port. The head further includes a first shaft mounted in a first bore of the head between the first port and the combustion chamber. The first shaft includes a first aperture extending therethrough and is rotatable between a first orientation wherein the first shaft blocks fluid communication between the first port and the combustion chamber and a second orientation wherein the first shaft permits fluid communication between the first port and the combustion chamber through the first aperture.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to internal combustion engines, and more particularly, the invention relates to a head assembly and valve-less internal combustion engine. 
         [0002]    Internal combustion engines are well known and are used in various applications. For example, internal combustion engines are used in automobiles, farm equipment, lawn mowers, and watercraft. Internal combustion engines also come in various sizes and configurations, such as two stroke or four stroke and ignition or compression. 
         [0003]    Typically, internal combustion engines ( FIG. 1 ) include a multitude of moving parts, for example, they include intake and exhaust valves, rocker arms, springs, camshafts, connecting rods, pistons, and a crankshaft. One of the problems with having a multitude of moving parts is that the risk of failure increases (particularly in the valve train) and efficiency decreases due to frictional losses. Special lubricants and coatings may be used to reduce friction and certain alloys may be used to prevent failure; however, even with these enhancements, the risk of failure and the frictional losses remain high. 
       BRIEF SUMMARY OF THE INVENTION 
       [0004]    These and other shortcomings of the prior art are addressed by the present invention, which provides a valve-less internal combustion engine that increases reliability and increases efficiency. 
         [0005]    According to one aspect of the invention, a head assembly for a valve-less internal combustion engine includes a head having a first port extending through the head and a surface defining a portion of a combustion chamber in fluid communication with the first port. The head further includes a first shaft mounted in a first bore of the head between the first port and the combustion chamber. The first shaft includes a first aperture extending therethrough and is rotatable between a first orientation wherein the first shaft blocks fluid communication between the first port and the combustion chamber and a second orientation wherein the first shaft permits fluid communication between the first port and the combustion chamber through the first aperture. 
         [0006]    According to another aspect of the invention, a head assembly for a valve-less internal combustion engine includes a head and a first shaft mounted in a first bore of the head. The head includes a surface defining a portion of a combustion chamber, an intake port extending through the head and in fluid communication with the combustion chamber for directing combustion air into the combustion chamber, and an exhaust port extending through the head and in fluid communication with the combustion chamber for directing exhaust gas out of the combustion chamber. The first shaft is mounted between the combustion chamber and a selected one of the intake and exhaust ports. The first shaft includes a first aperture extending therethrough and is rotatable between a first orientation wherein the first shaft blocks fluid communication between the combustion chamber and the selected one of the intake and exhaust ports and a second orientation wherein the first shaft permits fluid communication between the combustion chamber and the selected one of the intake and exhaust ports through the first aperture. 
         [0007]    According to another aspect of the invention, a valve-less internal combustion engine includes an engine block containing a rotating assembly and a head assembly. The rotating assembly includes a crankshaft positioned for rotation in the engine block, a piston adapted for linear movement in a cylinder between a first, non-compression position and a second, compression position, and a connecting rod for interconnecting the crankshaft and the piston such that rotation of the crankshaft causes the connecting rod to move the piston between the first and second positions. The head assembly includes a head having a first port extending through the head and in fluid communication with a combustion chamber defined by the cylinder and the head collectively. The head assembly further includes a first shaft mounted in a first bore of the head between the first port and the combustion chamber. The first shaft includes a first aperture extending therethrough and is rotatable between a first orientation wherein the first shaft blocks fluid communication between the first port and the combustion chamber and a second orientation wherein the first shaft permits fluid communication between the first port and the combustion chamber through the first aperture. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The subject matter that is regarded as the invention may be best understood by reference to the following description taken in conjunction with the accompanying drawing figures in which: 
           [0009]      FIG. 1  shows a prior art V-8 internal combustion engine; and 
           [0010]      FIG. 2  shows an internal combustion engine according to an embodiment of the invention; 
           [0011]      FIG. 3  shows a head assembly of the internal combustion engine of  FIG. 2 ; 
           [0012]      FIGS. 4A-4D  show the four strokes of the internal combustion engine of  FIG. 2 ; 
           [0013]      FIG. 5  shows an internal combustion engine according to an embodiment of the invention; 
           [0014]      FIGS. 6-7  show a head assembly of the internal combustion engine of  FIG. 5 ; 
           [0015]      FIG. 8  shows an intake and exhaust shaft of the internal combustion engine of  FIG. 5 ; and 
           [0016]      FIGS. 9A-9D  show the four strokes of the internal combustion engine of  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]    Referring to the drawings, an exemplary valve-less internal combustion (IC) engine according to an embodiment is shown generally at reference numeral  10 . The engine  10  includes a head assembly  11  having head  15  with at least one intake port  12 , at least one exhaust port  13 , a rotatable intake shaft  14  secured in a first bore  16  of the head  15 , and a rotatable exhaust shaft  17  secured in a second bore  18  of the head assembly  15 . The head assembly  11  may be part of or mounted on a standard engine block  20  having a rotating assembly  21  (piston  22 , connecting rod  23 , and crankshaft  24 ) contained therein. As shown, the rotating intake shaft  14  and rotating exhaust shaft  17  are positioned between the at least one intake port  12  and at least one exhaust port  13 , respectively, and a combustion chamber  26 . It should be appreciated that at least a portion of the combustion chamber  26  is defined by a surface of the head It should be appreciated that the number of head assemblies  11  on an engine will depend on the number of cylinders the engine has. A single cylinder engine is simply being used for discussion purposes. It should also be appreciated that the head assembly may be a single head design or of a two-part head design. 
         [0018]    For purposes of the following discussion, since the intake and exhaust shaft assemblies are the same, only the intake shaft  14  will be discussed. As illustrated in  FIG. 3 , the intake shaft  14  resides in the first bore  16  of the head  15  and is rotatably mounted in the bore  16  by bearings  30  and  31 . Seals  32 - 34  are positioned within grooves  36 - 38  of the bore  16  and grooves  39 - 41  of the intake shaft  14  to prevent gas leakage. The intake shaft  14  has a pre-determined diameter and includes an aperture  43  having a pre-determined diameter that extends through the shaft  14  to allow intake air to move through the intake port  12 , through the aperture  43 , and into the combustion chamber  26 . It should be appreciated that the shaft  14  may have multiple smaller apertures or a single large aperture, as shown. It should also be appreciated that the size of the aperture  43  is dependent on the shaft diameter and the desired timing. By changing the diameter of the aperture  43 , the timing of the engine may be changed. 
         [0019]    Referring to  FIG. 4 , the intake shaft  14  and exhaust shaft  17  are driven by a belt or chain (not shown) attached to the crankshaft  24  and rotate at a 4 to 1 ratio relative to the crankshaft  24 . During the four strokes of an engine, the intake shaft  14  and exhaust shaft  17  constantly rotate to position their apertures in the proper position relative to the ports  12 ,  13 . The “A” and “B” notations in the apertures  43  and  44  are used to show the rotation of the shafts  14  and  17  relative to the strokes. As shown, during the intake stroke, the aperture  43  of the intake shaft  14  is substantially aligned with the intake port  12  to allow air into the combustion chamber  26 . Aperture  44  of the exhaust shaft  17  is positioned such that exhaust shaft  17  closes the exhaust port  13  and air or gas is prevented from escaping the combustion chamber  26  through the exhaust port  13 . During the compression stroke, the apertures  43  and  44  of the intake and exhaust shafts  14  and  17  are both rotated to close off the intake port  12  and exhaust port  13 . During the power stroke, the apertures  43  and  44  of the intake and exhaust shafts  14  and  17  continue to keep the intake and exhaust ports  12 ,  13  closed. Finally, during the exhaust stroke, the intake shaft  14  continues to close the port  12  and exhaust shaft  17  is positioned such that the exhaust port  13  is now opened by substantially aligning the aperture  44  with the exhaust port  13 . The process then repeats. During this process, an overlapping occurs, i.e., as the exhaust port begins to close, the intake begins to open to complete the overlap which begins the charge (air runs into the combustion chamber). It should be appreciated that in a dual shaft system like being described, the separation of the apertures  43  and  44  may be adjusted to change the timing of the engine. 
         [0020]    Referring now to  FIG. 5 , a valve-less internal combustion (IC) engine according to an embodiment is shown generally at reference numeral  100 . Like engine  10 , engine  100  includes a head assembly  111  having a head  115  with an intake port  112  and an exhaust port  113 . The head assembly  111  may be part of or mounted to a standard engine block  120  having a rotating assembly assembly  121  (piston  122 , connecting rod  123 , and crankshaft  124 ) contained therein. The main difference between the engine  10  and  100  is that the engine  100  uses a single rotating shaft  114  to perform both intake and exhaust processes. 
         [0021]    Referring to  FIGS. 6-8 , as discussed above with respect to head assembly  11 , the rotating shaft  114  resides in a bore  116  of the head  115  and is rotatably mounted in the bore  116  by bearings  130  and  131 . Seals  132 - 134  are positioned within grooves  136 - 138  of the bore  116  and grooves  139 - 141  of the shaft  114  to prevent gas leakage. The shaft  114  has a pre-determined stepped diameter design and includes an intake aperture  143  having a pre-determined diameter and an exhaust aperture  144  having a pre-determined diameter. The intake aperture  143  extends through the shaft  114  to allow intake air to move through the intake port  112 , through the aperture  143 , and into combustion chamber  126 . The exhaust aperture  144  is positioned on a smaller diameter section of the shaft  114  and at a pre-determined angle relative to the intake aperture  143  to provide a separation therebetween. The exhaust aperture  144  extends through the shaft  114  to allow exhaust air or gas to move out of the combustion chamber  126 , through the exhaust aperture  144 , and out the exhaust port  113 . It should be appreciated that the shaft  114  may have multiple smaller apertures or a single large aperture, as shown, for each of the intake and exhaust apertures  143 ,  144 . It should also be appreciated that the size of the apertures  143  and  144  are dependent on the shaft diameter and the desired timing. By changing the diameter of the apertures  143  and  144 , the timing of the engine may be changed. It should be appreciated that the shaft  114  may be driven by a belt or chain via the crankshaft as described above with respect to engine  10 . 
         [0022]    As illustrated in  FIG. 9 , the intake and exhaust apertures  143  and  144  are separated to allow a four stroke engine to function properly. During the four strokes of the engine  100 , the shaft  114  constantly rotates to position the apertures  143 ,  144  in the proper position relative to the ports  112 ,  113 . As shown, during the intake stroke, the aperture  143  is substantially aligned with the intake port  112  to allow air into the combustion chamber  126 . Aperture  144  is positioned such that shaft  114  closes the exhaust port  113  and air or gas is prevented from escaping the combustion chamber  126  through the exhaust port  113 . During the compression stroke, the apertures  143  and  144  are both rotated to close off the intake port  112  and exhaust port  113 . During the power stroke, the apertures  143  and  144  continue to keep the intake and exhaust ports  112 ,  113  closed. Finally, during the exhaust stroke, the shaft  114  continues to close the port  112  and aperture  144  substantially aligns with the port  113  to open the exhaust port  113  and allow gas to escape the combustion chamber  126 . The process then repeats. During this process, an overlapping occurs, i.e., as the exhaust port begins to close, the intake begins to open to complete the overlap which begins the charge (air runs into the combustion chamber). 
         [0023]    The foregoing has described a valve-less internal combustion engine. While specific embodiments of the present invention have been described, it will be apparent to those skilled in the art that various modifications thereto can be made without departing from the spirit and scope of the invention. Accordingly, the foregoing description of the preferred embodiment of the invention and the best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation.