Abstract:
The present disclosure is directed toward implementations of internal combustion engines. The disclosure describes various embodiments of internal combustion engines where most of the internal elements rotate. Such engines allow for more efficient transfer of the energy created by combustion to the motive components of a vehicle such as wheels or propellers. One specific embodiment includes a rotating cylinder with a single piston which both reciprocates and rotates. The rotating motion of the piston is transferred to the cylinder, which in turn is connected to a driveshaft. Various embodiments of the invention employ differing numbers and configurations of pistons. All embodiments have the advantage of decreasing engine volume and increasing efficiency over traditional internal combustion engines.

Description:
PRIORITY CLAIM 
     This application discloses and claims subject matter that is disclosed in applicant&#39;s U.S. provisional application Ser. No. 61/478,026 that was filed Apr. 21, 2011. 
     BACKGROUND OF THE INVENTION 
     Traditional two and four stroke internal combustion engines are employed in many different applications. One primary application is to provide power for the motive force in cars, boats, airplanes and other vehicles. These types of engines generally employ a relatively high number of moving components, including camshafts, crankshafts, connecting rods, crankpins, and more, to transfer the motion from one or more reciprocating pistons into rotational movement. All these moving parts result in friction losses that decrease the efficiency of the engine. The high component count also results in engines with high frontal areas. 
     Developing a two stroke engine with fewer components reduces the amount of energy lost to friction where each engine part contacts a separate engine part. Reducing the number of engine parts reduces these friction losses and results in an engine with greater fuel efficiency. Reducing the number of components also allows the engine to be lighter and more compact. Smaller, lighter engines are relatively more fuel efficient than larger, heavier engines. Development of smaller engines, and especially engines with smaller frontal areas, is especially important in the aircraft industry because of the drag produced by airplane engines with larger frontal areas. 
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with a first aspect of the invention, an internal combustion engine is disclosed. The engine comprises an engine case and a rotating cylinder at least partially disposed within the engine case. The invention also includes one or more cam components connected to the engine case and are disposed around a portion of the rotating cylinder. The engine further includes reciprocating pistons which are at least partially disposed within the rotating cylinder. Cam path apertures are defined through the wall of the rotating cylinder. Cam rollers are connected to the reciprocating piston through the cam path apertures. The cam rollers are positioned adjacent to the cam components. 
     In one exemplary embodiment, the engine comprises two reciprocating pistons. The two reciprocating pistons may be positioned at least partially within the rotating cylinder and may be aligned within the rotating cylinder along a single axis. The reciprocating pistons may also be arranged to reciprocate in the same direction at the same time. In another exemplary embodiment, the two reciprocating pistons may be arranged to reciprocate in opposite directions at the same time. 
     A different exemplary embodiment comprises four reciprocating pistons. The four reciprocating pistons maybe positioned at least partially within the rotating cylinder and aligned within the rotating cylinder along a single axis. The reciprocating pistons may also be arranged to reciprocate in the same directions at similar times. In yet another exemplary embodiment, each of a pair of reciprocating pistons is arranged to reciprocate in the same directions at similar times and wherein each pair of reciprocating pistons are arranged to reciprocate in opposite directions at each time. 
     In another exemplary embodiment, the engine comprises three reciprocating pistons. The three reciprocating pistons maybe positioned at least partially within the rotating cylinder and aligned within the rotating cylinder along a single axis. The outer two reciprocating pistons may also be arranged to reciprocate in the same directions at similar times, while the third center reciprocating piston may be arranged to reciprocate in the opposite directions at similar times. 
     In another example embodiment, the cam components comprise a barrel cam, wherein the barrel cam has at least one curvilinear surface which defines a sinusoid. 
     Another embodiment of the present engine includes manifold ports defined through the wall of the rotating cylinder. Even yet another embodiment includes one or more fuel injection ports defined through the wall of the rotating cylinder. 
     Attendant the manifold ports, some embodiments include a manifold assembly. The manifold assembly may be comprised of a circular plate and a slotted circular plate. The two plates may be connected to each other such that the resulting component contains apertures which extend radially through the assembly. The final assembly may be disposed around the rotating cylinder adjacent to the manifold ports. 
     Further embodiments may include a rotating fuel injection system to inject fuel through the fuel injector ports. The rotating fuel injection system may include a nozzle and a segment connected to the nozzle configured to withstand high pressures. Between the two elements may be a valve. The rotating fuel injector assembly may further include a plunger rod positioned at an angle to the nozzle. The plunger rod may be configured to push fuel into the segment configured to withstand high pressures when the plunger is depressed. The plunger rod may also have a fuel injector cam roller connected to one end. Some embodiments also contain a fuel injector cam ring disposed around the fuel injector assembly. The fuel injector cam rollers may be configured to traverse the fuel injector cam ring as the rotating fuel injector assembly rotates. As the fuel injector cam rollers traverse the fuel injector cam ring, they may be configured to reciprocate the plunger rod. Further embodiments of the rotating fuel injector assembly may include an electrical slip ring. Even further embodiments of the rotating fuel injector assembly may include a rotary fluid coupling. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING VIEWS 
       The invention is further described in connection with the accompanying drawings. 
         FIG. 1(   a ) is an isometric depiction of the disclosed single piston engine configuration. 
         FIG. 1(   b ) is an isometric depiction of a single piston engine configuration of the present invention, with one of the stationary cam components removed for a more clear view of the piston, its barrel cam rollers, and the cylinder with its slotted cam paths. 
         FIGS. 2(   a   1 ) and  2 ( a   2 ) show a starting position of the cylinder, with the piston at the top dead center position. 
         FIGS. 2(   b   1 ) and  2 ( b   2 ) show the relative position of the cylinder and piston after 45 degrees of rotation. 
         FIGS. 2(   c   1 ) and  2 ( c   2 ) show the relative position of the cylinder and piston after 90 degrees of rotation, positioning the piston at the bottom dead center position. 
         FIGS. 2(   d   1 ) and  2 ( d   2 ) show the relative position of the cylinder and piston after 135 degrees of rotation. 
         FIG. 3(   a   1 ) is an isometric depiction of the stationary manifold with respect to the other engine components. 
         FIG. 3(   a   2 ) is the same isometric depiction as  FIG. 3(   a   1 ) with a portion of the manifold assembly cut away for clarity. 
         FIGS. 3(   b   1 ) and  3 ( b   2 ) show the piston in a position just prior to the bottom dead center position, with the rotating cylinder manifold port apertures uncovered and lined up with frusto-pyramidal shaped slots in the manifold. 
         FIGS. 3(   c   1 ) and  3 ( c   2 ) show the piston at the bottom dead center position, with the rotating cylinder manifold port apertures uncovered and partially lined up with frusto-pyramidal shaped slots in the manifold. 
         FIGS. 3(   d   1 ) and  3 ( d   2 ) show the piston in a position just after the bottom dead center position, with the rotating cylinder manifold port apertures uncovered and lined up with frusto-pyramidal shaped slots in the manifold. 
         FIG. 4  illustrates the integration of direct injection for the engine of the present invention;  FIGS. 4(   a   1 ) and  4 ( a   2 ) show a unit direct injector reconfigured to fit within a smaller diametrical shape, the latter Figure having a portion of the injector removed for clarity. 
         FIGS. 4(   b   1 ) and  4 ( b   2 ) show two such re-shaped unit direct injectors integrated so as to fit around the rotating cylinder, and depict how the cam roller assembly follows a modified cylindrical cam path and engages the fuel injector plunger. 
         FIGS. 4(   c   1 ) and  4 ( c   2 ) isometrically depicts the integrated unit direct injection system, including the rotary fluid coupling and electrical slip ring. 
         FIG. 5  illustrates the operation of a dual combustion chamber, two piston engine configuration of the present invention arranged in a coaxial and tandem manner over one complete piston cycle, or one-half of a full cylinder rotation, the cylinder rotation being counterclockwise. 
         FIGS. 5(   a   1 ) and  5 ( a   2 ) show a starting position of the cylinder, with the left piston at top dead center and the right piston at bottom dead center. 
         FIGS. 5(   b   1 ) and  5 ( b   2 ) show the relative position of the cylinder and pistons after 45 degrees of rotation. 
         FIGS. 5(   c   1 ) and  5 ( c   2 ) show the relative position of the cylinder and pistons after 90 degrees of rotation, positioning the left piston at bottom dead center and the right piston at top dead center. 
         FIGS. 5(   d   1 ) and  5 ( d   2 ) show the relative position of the cylinder and pistons after 135 degrees of rotation. 
         FIG. 6  illustrates the operation of a dynamically balanced single cylinder, opposed piston engine configuration of the present invention over one complete piston cycle, or one-half of a full cylinder rotation, the cylinder rotation being counterclockwise. 
         FIGS. 6(   a   1 ) and  6 ( a   2 ) show a starting position of the cylinder, with the pistons at top dead center. 
         FIGS. 6(   b   1 ) and  6 ( b   2 ) show the relative position of the cylinder and pistons after 45 degrees of rotation. 
         FIGS. 6(   c   1 ) and  6 ( c   2 ) show the relative position of the cylinder and pistons after 90 degrees of rotation, positioning the pistons at bottom dead center. 
         FIGS. 6(   d   1 ) and  6 ( d   2 ) show the relative position of the cylinder and pistons after 135 degrees of rotation. 
         FIG. 7  illustrates the operation of the preferred embodiment of the engine of the present invention over one complete piston cycle, or one-half of a full cylinder rotation, the cylinder rotation being counterclockwise. 
         FIGS. 7(   a   1 ) and  7 ( a   2 ) show a starting position of the cylinder, with intake and exhaust ports open in the right side of the cylinder assembly. 
         FIGS. 7(   b   1 ) and  7 ( b   2 ) show the relative position of the cylinder, pistons, and intake and exhaust ports after 22.5 degrees of rotation. 
         FIGS. 7(   c   1 ) and  7 ( c   2 ) show the relative position of the cylinder, pistons, and intake and exhaust ports after 45 degrees of rotation. 
         FIGS. 7(   d   1 ) and  7 ( d   2 ) show the relative position of the cylinder, pistons, and intake and exhaust ports after 67.5 degrees of rotation. 
         FIGS. 7(   e   1 ) and  7 ( e   2 ) show the relative position of the cylinder, pistons, and intake and exhaust ports after 90 degrees of rotation. 
         FIGS. 7(   f   1 ) and  7 ( f   2 ) show the relative position of the cylinder, pistons, and intake and exhaust ports after 112.5 degrees of rotation. 
         FIGS. 7(   g   1 ) and  7 ( g   2 ) show the relative position of the cylinder, pistons, and intake and exhaust ports after 135 degrees of rotation. 
         FIGS. 7(   h   1 ) and  7 ( h   2 ) show the relative position of the cylinder, pistons, and intake and exhaust ports after 157.5 degrees of rotation. 
         FIG. 8  illustrates a potential oil channel arrangement of the disclosed invention. 
         FIG. 9  illustrates the operation of a three piston version of the engine of the present invention over one complete piston cycle, or one-half of a full cylinder rotation, the cylinder rotation being counterclockwise. 
         FIGS. 9(   a   1 ) and  9 ( a   2 ) show a starting position of the cylinder, with intake and exhaust ports open in the right side of the cylinder assembly. 
         FIGS. 9(   b   1 ) and  9 ( b   2 ) show the relative position of the cylinder, pistons, and intake and exhaust ports after 22.5 degrees of rotation. 
         FIGS. 9(   c   1 ) and  9 ( c   2 ) show the relative position of the cylinder, pistons, and intake and exhaust ports after 45 degrees of rotation. 
         FIGS. 9(   d   1 ) and  9 ( d   2 ) show the relative position of the cylinder, pistons, and intake and exhaust ports after 67.5 degrees of rotation. 
         FIGS. 9(   e   1 ) and  9 ( e   2 ) show the relative position of the cylinder, pistons, and intake and exhaust ports after 90 degrees of rotation. 
         FIGS. 9(   f   1 ) and  9 ( f   2 ) show the relative position of the cylinder, pistons, and intake and exhaust ports after 112.5 degrees of rotation. 
         FIGS. 9(   g   1 ) and  9 ( g   2 ) show the relative position of the cylinder, pistons, and intake and exhaust ports after 135 degrees of rotation. 
         FIGS. 9(   h   1 ) and  9 ( h   2 ) show the relative position of the cylinder, pistons, and intake and exhaust ports after 157.5 degrees of rotation. 
     
    
    
     DETAILED DESCRIPTION 
     Improved engine designs that include reduced numbers of parts, lower friction losses, reduced vibration, and smaller frontal area would greatly benefit automotive and aircraft applications. Frontal area reductions would be especially beneficial for aircraft applications, due to the reduced drag contribution of the engines and their cowlings. Traditional piston engine designs, with piston rods, crankshafts, and cam driven valves are inherently burdened by high part counts, sizable friction losses, and large frontal areas. Even advancements in rotary engines and opposed piston configurations continue to be limited in the efficiencies they can produce in many of these attribute areas. 
     A new engine configuration should be lighter in weight and preferably have a reduced frontal area profile for improved installation suitability. For automotive applications, a reduced frontal area profile would permit the engine to fit compactly in narrow spaces. For light aircraft applications, a reduced frontal area profile would reduce drag associated with large frontal area engine cowlings. 
     Compared to a current state-of-the-art production four cylinder in-line engine having comparable performance, the engine of the present invention provides previously unanticipated—yet substantial—improvements in frontal area, the reduction of friction losses and number of parts in the engine assembly, and the nearly complete elimination of vibration, due to the use of a rotating cylinder and barrel cam rollers. 
     Unless otherwise specified in this description, the components of the present invention may be made from metal including titanium, steel stainless steel, aluminum, or any other metal suitable for use in an internal combustion engine. Components may also be made from non-metallic materials, provided such materials possess properties suitable for the loads and temperatures typically present in engine applications. Additionally, unless otherwise specified in the description, when components are attached to each other, they may be attached using various welding techniques, with screws, nails, glue, or by any suitable technique for attaching metal or non-metal components to other metal or non-metal components. 
     1. General Description of Engine Components 
       FIGS. 1(   a ) and  1 ( b ) illustrate one exemplary embodiment of the present invention. One embodiment of the engine configuration of the present invention comprises a stationary engine case assembly  1000  (which has a portion of it cut away for clarity), and a rotating cylinder assembly  2000 . 
     Stationary engine case  1000  comprises a hollow cylinder component  1010  and circular end components  1020 . Stationary engine case  1000  may further comprise cylindrical end caps  1030 . Hollow cylinder component  1010  may have apertures (not shown) defining holes through the walls of hollow cylinder component  1010 . The apertures may allow for the intake and exhaust of air (the operation of which is described in further detail later) or the injection of fuel. 
     In one example embodiment, circular end components  1020  have circular openings near the center of circular end components  1020 . Cylindrical end caps  1030  may be a hollow cylindrical component. Cylindrical end caps  1030  may be attached to circular end components  1020  such that the hollow center portion of cylindrical end caps  1030  line up with the circular openings of circular end components  1020 . In some embodiments the circular openings in the circular end components  1020  and the center hollow portion of cylindrical end caps  1030  are the same size. In at least one embodiment, components  1030 ,  1020 , and  1010  are made from a single piece of metal as a unitary component. 
     Stationary engine case  1000  may further comprise cylindrical cam components  1200  and  1201 . Cylindrical cam components  1200  and  1201  may generally be metal cylinders with an aperture defined through each component&#39;s center. Further, each cylindrical cam component  1200  and  1201  has two different opposing ends  1210 ,  1220  and  1211 ,  1221  respectively. Surfaces  1220  and  1221  are flat, outer surfaces which face toward the circular end components  1020 . Inner surfaces  1210  and  1211  face each other. In one embodiment, inner surfaces  1210  and  1211  are curvilinear in shape, with the surfaces defining peaks where the cylindrical cam components  1200  and  1201  are relatively thick and valleys where cylindrical cam components  1200  and  1201  are relatively thin. In one example embodiment, inner surfaces  1210  and  1211  define a sinusoidal shape of peaks and valleys. 
     Cylindrical cam components  1200  and  1201  may be disposed within hollow cylinder component  1010 . In some embodiments, cylindrical cam components  1200  and  1201  are attached to hollow cylinder component  1010 . In at least one embodiment, cylindrical cam components  1200  and  1201  are secured to hollow cylinder component  1010  through bolted or pinned connections. In one embodiment, the end surface  1221  of cylindrical cam component  1201  abuts one of the circular end components  1020 . Cylindrical cam component  1201  may or may not be physically attached to circular end components  1020 . In one embodiment, cylindrical cam component  1200  is positioned further toward the middle of the stationary engine case  1000  than cylindrical cam component  1201 . In further embodiments, cylindrical cam components  1200  and  1201  are aligned such where inner surface  1210  defines a peak, adjacent inner surface  1211  defines a valley, and where inner surface  1211  defines a peak, adjacent inner surface  1210  defines a valley. In some embodiments, cylindrical cam components  1200  and  1201  are positioned apart from each other such that there is space between inner surfaces  1210  and  1211 . 
       FIG. 1(   a ) and  FIG. 1(   b ) also depict rotating cylinder assembly  2000 . Rotating cylinder assembly  2000  has a rotating cylinder  2100 , end caps  2101 , and drive shafts  2103 . Rotating cylinder  2100  is generally hollow with various apertures defined through its outer surface. In some embodiments, rotating cylinder  2100  has manifold port apertures  2130  defined through the wall of rotating cylinder  2100 . 
     Manifold port apertures  2130  may be generally rectangular in shape. In other embodiments, the edges of the manifold port apertures  2130  angle inward toward the interior of rotating cylinder  2100 , wherein the manifold port apertures  2130  generally define a frusto-pyramidal shape with an asymmetric base. Other embodiments contemplate different shaped apertures. In at least one embodiment, manifold port apertures  2130  are placed away from the region occupied by the cylindrical cam components  1200  and  1201  such that no portion of either cam component overlaps the ports  2130 . 
     Rotating cylinder  2100  may further have at least one fuel injection port aperture  2120  defined through its wall. In some embodiments the rotating cylinder  2100  has two fuel injection port apertures  2120  which may be located on opposite sides of the hollow cylinder component  1010 . Fuel injection port apertures  2120  may define a hole of any shape, but in at least one embodiment, the shape is round. Fuel injection port apertures  2120  may be positioned even further away from cylindrical cam components  1200  and  1201  than the manifold port apertures  2130 . 
     One particular embodiment (not shown) of the present invention includes a single fuel injection port aperture  2120 . In this embodiment the driveshaft  2103  furthest from the cylindrical cam components  1200  and  1201  has a hollow channel running through the driveshaft lengthwise. The hollow channel ends in fuel injection port aperture  2120  where the hollow channel opens up into the hollow portion of Rotating cylinder  2100 . 
     Finally, rotating cylinder  2100  may include slotted cam path apertures  2110 . One embodiment includes two slotted cam path apertures  2110  defined on opposing sides on rotating cylinder  2100 . These slotted cam path apertures  2110  generally define a rectangular area where the two ends of the rectangle form semi-circles. These slotted cam path apertures  2110  may be located generally in the region where cylindrical cam components  1200  and  1201  encircle the Rotating cylinder  2100 . In some embodiments, the slotted cam path apertures  2110  are located such that a portion of either cylindrical cam component  1200  or  1201  overlaps the slotted cam path apertures at all times during the operation of the invention. 
       FIG. 1(   a ) and  FIG. 1(   b ) further depict reciprocating piston assembly  2200 . Reciprocating piston assembly  2200  may include reciprocating piston  2210  and barrel cam rollers  2220 . Reciprocating piston assembly  2200  may be positioned inside the hollow portion of rotating cylinder  2100 . Barrel cam rollers  2220  may include straight roller elements  2221  and tapered barrel cam roller elements  2222 . In at least one embodiment, reciprocating piston assembly  2200  includes two barrel cam rollers  2220  positioned on opposite sides of reciprocating piston  2210 . 
     Reciprocating piston  2210  may be a standard engine piston that is well known in the art. Reciprocating piston  2210  may include a number of piston rings  2230 . The exact number of piston rings included in the invention may range between 1 and 5. A person of ordinary skill in the art would know to use the number of piston rings that optimizes combustion chamber sealing, which may be readily determined through simple experimentation that is well known in the art. Additionally, as is known in the art, one end of reciprocating piston  2210  may have a variety of features that improve engine efficiency. For example, the end may have a concave or other hollow shaped portion. 
     The straight roller elements  2221  of reciprocating piston assembly  2200  may generally be cylindrical pieces of metal. In some embodiments, straight roller elements  2221  have a hollow channel running through their centers. 
     Tapered barrel cam roller elements  2222  may have a wide, circular top portion which tapers to a smaller, circular base portion. In general, this shape may be referred to as frustoconical. The diameter of the base portions of tapered barrel cam roller elements  2222  may be the same size as the diameter of the straight roller elements  2221 . Similar to straight roller elements  2221 , tapered barrel cam roller elements  2222  may have a hollow channel running through its center. In one embodiment, when a tapered barrel cam roller element  2222  is positioned on top of a straight roller element  2221 , the hollow channels of both components may line up to make a single, connected hollow channel. 
     In other embodiments, straight roller elements  2221  and tapered barrel cam roller elements  2222  may be formed together from a single element. In these embodiments, the single element has two different sections—a tapered section and a straight section, with the straight section having the same diameter as the diameter of the element where on the small end of the taper. 
     Barrel cam rollers  2220  are attached to reciprocating piston  2210  in a rotatably independent fashion. In one embodiment, at the point where barrel cam rollers  2220  are to be attached to reciprocating piston  2210 , reciprocating piston  2210  has a round slot extending toward the center of the piston. In embodiments where two barrel cam rollers  2220  attach to reciprocating piston  2210 , reciprocating piston  2210  may have two round slots on opposite sides of the piston. Further, both slots may extend to the center of the piston and connect such that the reciprocating piston  2210  has one long slot extending all the way through it. The slot may be sized such that when straight roller elements  2221  and tapered barrel cam roller elements  2222  are placed over the slot, the slot aligns with the hollow channels in the elements and forms a single, long, interconnected channel. 
     In some embodiments, pin elements may be press fit into or otherwise attached to the round slots in reciprocating piston  2210 . Each pin would extend outwardly beyond the edge of the piston. Then, straight roller elements  2221  and tapered barrel cam roller elements  2222  may be slid over each pin. In one embodiment, each pin element would extend slightly beyond the end of the tapered barrel cam roller elements  2222 . In these embodiments, a capping element may be fit over and attached to each pin. In this manner, straight roller elements  2221  and tapered barrel cam roller elements  2222  would be prevented from sliding off the pin. Through this connection, tapered barrel cam roller elements  2222  and straight roller elements  2221  would be able to rotate independent of the piston and of each other. 
     In embodiments where reciprocating piston  2210  has a single channel extending all the way through the element, there may be a single, long pin element. The pin element may be positioned in the channel in piston  2210  and extend beyond the opposed edges of the piston. In a manner similar to that described above, the straight roller elements  2221  and tapered barrel cam roller elements  2222  may be positioned over the pin element and capped. 
     As depicted in  FIGS. 3(   a   1 )- 3 ( d   2 ), the present invention may further comprise a manifold assembly  1300 . Manifold assembly  1300  may include slotted component  1330  and plate component  1340 . Slotted component  1330  may be a circular plate with a circular aperture defined through its center comprised of flat portions  1310  and raised portions  1320 . The flat portions  1310  and the raised portions  1320  may alternate circumferentially around the slotted component  1330 . Raised portions  1320  may extend from the edge of the slotted component  1330  to its center aperture. In some embodiments, the raised portions  1320  are a frusto-pyramidal shape with the base near the outer edge of the slotted component  1330 . Other embodiments contemplate the raised portions  1320  as other shapes. 
     The plate component  1340  may be attached to the slotted component  1330  with the plate component  1330  connected to the raised portions  1320  of component  1330 . Once connected, components  1330  and  1340  comprise the manifold assembly  1300 . The manifold assembly  1300  may then have a series of frusto-pyramidal shaped slots  1350  spaced apart around the circumference of the assembly. In other embodiments, manifold assembly  1300  may be made from a single component. In operation, the frusto-pyramidal shaped slots  1350  may be used as air intake and exhaust ports. In at least one embodiment, every other frusto-pyramidal shaped slot  1350  is used for air intake and the other the frusto-pyramidal shaped slots  1350  are used for air exhaust. In other embodiments, the intake frusto-pyramidal shaped slots  1350  and the exhaust frusto-pyramidal shaped slots  1350  may be different in number. In further embodiments, multiple manifold assemblies  1300  may be employed in a single engine, with each manifold assembly  1300  being responsible solely for intake or for exhaust. Additionally, the sequence of the ports may be different than every other. The invention contemplates all combinations of numbers and sequences of using frusto-pyramidal shaped slots  1350  as intake and/or exhaust ports. 
     As depicted in  FIGS. 4(   a   1 )- 4 ( c   2 ), the present invention may further comprise an integrated unit direct injection system  2300 . Integrated unit direct injection system  2300  may comprise single or multiple fuel injector assemblies  2254 , which fasten to and rotate with the rotating cylinder  2100  (not shown). In such an embodiment, the nozzle assemblies  2241  of the fuel injector assemblies  2254  may be inserted into fuel injection port apertures  2120  (not shown). Integrated unit direct injection system  2300  may further comprise rotary fluid coupling  2246  and electrical slip ring  2249 . A person of ordinary skill in the art would know to arrange concentric hollow cylindrical portions for each of the rotary fluid coupling  2246  and electrical slip ring  2249 , the inner portions of which may be positioned around and rotate with the rotating cylinder  2100  and the outer portions of which may stay stationary with the stationary engine case  1000  (not shown). The outer portion of the rotary fluid coupling  2246  may have fluid connection ports  2247  that communicate with the rest of the engine&#39;s fuel delivery system, which may be configured in a typical manner common in the art. The outer portion of the electrical slip ring  2249  may have electrical connection ports  2250  that communicate with the rest of the engine&#39;s ignition system, which may be configured in a typical manner common in the art. The inner portions are in communication with the fuel injector assemblies  2254  so as to deliver fuel and electrical power to the injectors. Fuel ports and electrical connections  2259  may be configured in the rotary fluid coupling  2246  and electrical slip ring  2249  for transfer of fuel and electricity to and from the fuel injector assemblies  2240 , which may also have fuel ports and electrical connections  2259  configured thereon. The sizing, sealing, function, and fastening of the various portions of the rotary fluid coupling  2246  and electrical slip ring  2249  may be readily determined through simple analysis and experimentation that are well known in the art. 
     Fuel injector assembly  2254  may comprise a unit injector  2240 , which may further comprise a nozzle assembly  2241 , plunger assembly  2242 , pump assembly  2255 , high pressure portion  2256 , and solenoid assembly  2257 . In some embodiments, the unit injector  2240  may be configured as a traditional unit injector with a shape and configuration which would be readily familiar to a person of ordinary skill in the art. In such an embodiment, the traditional unit injector&#39;s plunger and fuel pump portion  2258  would be aligned with the nozzle assembly  2241  and high pressure portion  2256 . Another embodiment may instead arrange the pump assembly  2255  at an angle to the nozzle assembly  2241  and high pressure portion  2256  so as to minimize the radial space occupied by the rotating assembly. In such an embodiment, fuel injector assembly  2254  may further comprise fuel injector cam slots  2261  that may be oriented in the direction of the pump assembly  2255 . This embodiment of the fuel injector assembly  2254  may also comprise fuel injector plunger rod  2245 , which may have a rod shape at one end that may press upon the plunger assembly  2242  and a yoke configuration on its other end. Such fuel injector plunger rod  2245  may also have cylindrical apertures on the yoke end. The fuel injector assembly  2254  may further comprise fuel injector cam roller  2243 , which may have a bushing or bearing at its inner diameter interface, and which may further be positioned within the yoke of the fuel injector plunger rod  2245 . Some embodiments of the fuel injector assembly  2254  may further comprise fuel injector roller pin  2252 , which may be press fit into either the yoke assembly of the fuel injector plunger rod  2245 , the fuel injector cam roller  2243 , or both. Other exemplary fuel injector assemblies  2254  may also comprise one or more fuel injector secondary rollers  2253  that may have a bushing or bearing within its inner diameter and which may be positioned onto the fuel injector roller pin  2252  through a press fit or other fastening method, and may further be positioned with its outer diameter aligned with and rolling upon the fuel injector cam slots  2261  of the fuel injector assembly  2254 . 
     In some embodiments of the integrated unit direct injection system  2300 , a fuel injector cam ring  2244  may be placed around the fuel injector assembly  2254 . In at least one embodiment, fuel injector cam ring  2244  may be hollow, with the internal hollow portion configured as a fuel injector cam surface  2262  which fuel injector cam roller  2243  may roll upon. A person of ordinary skill in the art would know to configure fuel injector cam surface  2262  in a manner that would allow integrated unit direct injection system  2300  to be pressurized appropriately as fuel injector cam roller  2243  embodied as described rolls upon fuel injector cam surface  2262  during rotation of cylinder assembly  2100 . 
     2. Combination of the Assemblies 
     The rotating cylinder assembly  2000  may be disposed within the stationary engine case assembly  1000 . The cylindrical cam components  1200  and  1201  may be situated around the rotating cylinder  2100 , but are not connected to the cylinder. Instead, there may be a small space between components  1200 ,  1201  and  2100  so as to allow rotating cylinder  2100  to rotate during the operation of the engine. The cylindrical cam components  1200  and  1201  are disposed about rotating cylinder  2100  near the slotted cam path apertures  2110 . 
     In at least one embodiment, the reciprocating piston  2210  is positioned inside of the rotating cylinder  2100 . The outer diameter size of the reciprocating piston  2210  relative to the internal diameter of the rotating cylinder  2100  may be similar to sizes well know in the art for other internal combustion engines pistons and engine block cavities. 
     When the reciprocating piston  2210  is positioned inside the rotating cylinder  2100 , the engine assembly defines a combustion chamber  2400 , as shown in  FIG. 1(   b ). The combustion chamber  2400  is analogous to combustion chambers in standard internal combustion engines. 
     The round slots extending internally to reciprocating piston  2210  may line up with the slotted cam path apertures  2110  of the rotating cylinder  2100 . As described above, the barrel cam rollers  2220  may be attached to the reciprocating piston  2210 . Some embodiments may include a friction reducing element placed between straight roller elements  2221  and tapered barrel cam roller elements  2222  to reduce the friction forces on the elements as they rotate independently. In at least one embodiment, the straight roller elements  2221  are the same thickness as the wall of the rotating cylinder  2100 . In other embodiments, straight roller elements  2221  may be thinner or thicker than the wall of the rotating cylinder  2100 . 
     The round slots in the reciprocating piston  2210  and the slotted cam path apertures  2110  may be aligned with the cylindrical cam components  1200  and  1201  such that when the barrel cam rollers  2220  are attached to the reciprocating piston  2210  through the slotted cam path apertures  2110 , the barrel cam rollers  2220  fit between the cylindrical cam components  1200  and  1201 . The cylindrical cam components  1200  and  1201  may be spaced apart a distance about equal to the diameter of the largest diameter section of the tapered barrel cam roller elements  2222 . The curvilinear surfaces of the cylindrical cam components  1200  and  1201  and the tapered barrel cam roller elements  2222  may be configured in such a way that the surface of the tapered barrel cam roller elements  2222  may be in substantial contact with the curvilinear surfaces of the cylindrical cam components  1200  and  1201  as the tapered barrel cam rollers  2222  traverse around the cylindrical cam components  1200  and  1201  as the engine operates. 
     As depicted in  FIGS. 3(   a   1 )- 3 ( d   2 ), the manifold assembly  1300  may be attached to the hollow cylindrical component  1010  and positioned around the rotating cylinder  2100  adjacent to the manifold port apertures  2130 . Manifold assembly  1300  is not connected to rotating cylinder  2100  so that rotating cylinder  2100  may rotate as manifold assembly  1300  remains stationary. The manifold assembly may be positioned such that as the rotating cylinder  2100  rotates, at times the manifold port apertures  2130  line up with the slots  1350 , creating a single channel extending between the two components, and at other times, the manifold port apertures  2130  line up with the solid portions of the manifold assembly  1300 . When the slots  1350  and the manifold port apertures  2130  at least partially line up, there may be an open path for air to travel from the inside of the rotating cylinder  2100  to outside of the hollow cylinder component  1010 . 
     The integrated unit direct injection system  2300 , as depicted in  FIGS. 4(   c   1 ) and  4 ( c   2 ) may be disposed around the rotating cylinder  2100  and the nozzles  2241  inserted into the fuel injection port apertures  2120 . Other portions of the unit direction injection system  2300  may be attached to the hollow cylindrical component  1010  (not shown) of the stationary engine case  1000  (not-shown). 
     3. Operation of the Engine 
       FIGS. 2(   a   1 )- 2 ( d   2 ) illustrate the operation of a single cylinder, single piston engine configuration of the present invention over one complete piston cycle, or one-half of a full cylinder rotation, the cylinder rotation being counterclockwise.  FIGS. 2(   a   1 ) through  2 ( d   2 ) illustrate the relative position of the cylinder, piston, and manifold ports at approximately 45 degree increments. Cylinder angle phi is indicated by the small triangle and arrowed arc. 
     In  FIGS. 2(   a   1 ) and  2 ( a   2 ), the piston is shown at “Top Dead Center,” or TDC. Fuel may be injected through fuel injection port apertures  2120  and ignition accomplished through methods well known in the art (i.e. spark ignition or compression ignition). When ignition occurs, reciprocating piston assembly  2200  is pushed down the rotating cylinder  2100 , forcing the barrel cam rollers  2220  to follow the sinusoidal cam paths of cylindrical cam components  1200  and  1201 , imparting a rotational moment upon the reciprocating piston assembly  2200 . This rotational moment within reciprocating piston assembly  2200  is then transferred from the straight roller elements  2221  on the barrel cam rollers  2220  into the rotating cylinder  2100  through the cam path apertures  2110  in the rotating cylinder  2100 , thereby creating a rotational motion within the entire rotating cylinder assembly  2000 . 
       FIGS. 2(   b   1 ) and  2 ( b   2 ) depict the resulting positions of the reciprocating piston assembly  2200  and rotating cylinder  2100  after the reciprocating piston  2210  has travelled half way down its path within the rotating cylinder  2100  during its combustion stroke and the resultant rotating cylinder assembly  2000  rotation of 45 degrees. 
       FIGS. 2(   c   1 ) and  2 ( c   2 ) depict the resulting positions of the of the reciprocating piston assembly  2200  and rotating cylinder assembly  2000  after the piston has travelled all the way down the rotating cylinder  2100  to its “Bottom Dead Center,” or BDC, position and the resultant rotating cylinder assembly  2000  rotation of 90 degrees. As the reciprocating piston  2210  approaches, reaches, and departs its BDC position, it uncovers the manifold port apertures  2130  within the rotating cylinder  2100  thereby allowing exhaust gases to escape the cylinder and intake air to enter the cylinder (further description provided below). Upon reaching BDC, the reciprocating piston assembly  2200  is forced back up the rotating cylinder  2100  toward TDC through its rotational inertia and the cam path constraints formed by cylindrical cam components  1200  and  1201 . 
       FIGS. 2(   d   1 ) and  2 ( d   2 ) depict the resulting positions of the reciprocating piston assembly  2200  and the rotating cylinder assembly  2000  after the reciprocating piston  2210  has travelled half way back up its path toward TDC and the resultant rotating cylinder assembly  2000  rotation of 135 degrees. During the piston&#39;s travel toward TDC, any air in the combustion chamber  2400  is compressed for the next ignition and combustion cycle upon reaching TDC, occurring at a rotating cylinder assembly  2000  rotation of 180 degrees. 
     4. Oil Channels 
     As with most internal combustion engines, the embodiments of this invention require the application of oil to bearing surfaces in order to assist the engine operating in an efficient and cool manner. The application of oil to bearing surfaces and other surfaces where friction occurs is accomplished through the addition of oil channels into the key components. Further, as is well understood in the art, the oil may be applied under pressure so as to force the oil through the various oil channels, create a constant flow of oil through the system, and provide hydrostatic oil pressure to bearing surfaces. 
     In one example, as shown in  FIG. 8 , the driveshaft  2103  contains a hollow oil channel running lengthwise through it. This hollow oil channel may connect to hollow oil channels that run radially from near the center of end caps  2101  toward the edge of the end caps. Near the edge, the hollow oil channels of end caps  2101  may connect with hollow oil channels in rotating cylinder  2100 . The hollow oil channels in rotating cylinder  2100  may run lengthwise through the wall toward the opposite driveshaft  2103 . 
     In some examples, the hollow oil channels of rotating cylinder  2100  may contain exit channels that extend inward toward the hollow center of the cylinder. As the oil exits these exit channels, the oil may lubricate the inner surface of the rotating cylinder  2100  and the outer surface of reciprocating piston  2210 . Reciprocating piston  2210  may further have one or more shallow grooves running lengthwise carved into it. In some embodiments, the grooves start near the end of the piston opposite the end with the piston rings. The grooves may run about halfway down the piston. In other embodiments, the grooves may be shorter or longer than half the length of the piston  2210 . The end of each groove may end in a channel cut into the piston  2210 . The channel may extend radially inward toward the center of the piston  2210 . These channels may intersect with the round slot of piston  2210  previously described. As the oil exits into the cavity between the piston  2210  and the inner wall of the rotating cylinder  2100 , the grooves of the piston  2210  may collect the oil and direct it toward the round slot or slots. 
     The pin element that may connect the barrel cam rollers  2220  to the reciprocating piston  2210  may also contain oil channels. As the oil is directed towards the round slot of the piston  2210 , the oil may enter the oil channels cut into the pin element. The oil channels in the pin element may further align with oil channels in the straight roller elements  2221  and the tapered barrel cam roller elements  2222 . Each of the straight roller elements  2221  and tapered barrel cam roller elements  2222  may contain oil exit ports. As the oil may exit through the ports in the straight roller elements  2221 , the oil may lubricate surfaces where the straight roller elements  2221  move against the wall of the rotating cylinder  2100  in the slotted cam path apertures  2110 . As the oil may exit the tapered barrel cam roller elements  2222 , the oil may lubricate both the outer surface of the tapered barrel cam roller elements  2222  and the surfaces of the cylindrical cam components  1200  and  1201 . A person of ordinary skill in the art would know to arrange engine case assembly  1000  in such a manner as to collect the circulating oil in an oil pan or other similar reservoir and recirculate it through traditional pump and filter assemblies. 
       FIG. 8  provides a single example of how oil channels may be implemented in an engine of the present invention.  FIG. 8  illustrates a portion of the engine cut-away with the oil channels highlighted in black. Other embodiments may have oil channels in different locations or connecting through different elements. 
       FIG. 3  illustrates a means by which exhaust gases can be scavenged from the rotating cylinder  2100  and intake air can be reintroduced into the cylinder.  FIG. 3(   a   1 ) is an isometric depiction of the stationary manifold assembly  1300  with respect to the other engine components, while  FIG. 3(   a   2 ) is the same isometric depiction with a portion of the manifold assembly  1300  cut away for clarity, revealing frusto-pyramidal shaped slots  1350 . 
       FIGS. 3(   b   1 ) and  3 ( b   2 ) show the reciprocating piston assembly  2200  in a position just prior to bottom dead center, with the manifold port apertures  2130  in the rotating cylinder  2100  uncovered and lined up with some of the frusto-pyramidal shaped slots  1350  in the manifold assembly  1300 , thereby allowing the exhaust gases in the rotating cylinder  2100  to escape from the cylinder. 
     Upon further rotation of the rotating cylinder assembly  2000 , the manifold port apertures  2130  in the rotating cylinder  2100  line up partially with all of the frusto-pyramidal shaped slots  1350  in the manifold assembly  1300 , as depicted in  FIG. 3(   c   1 ) and  FIG. 3(   c   2 ), showing the rotating cylinder  2100  at 90 degrees and the reciprocating piston assembly  2200  at BDC. In this configuration, the exhaust gases continue to escape out the frusto-pyramidal shaped slots  1350  in the manifold assembly  1300  while intake air is also allowed to enter the rotating cylinder  2100 , scavenging exhaust gases further. 
     Finally, as the rotating cylinder assembly  2000  continues to rotate and as the reciprocating piston assembly  2200  moves back up the rotating cylinder  2100  away from BDC, as shown in  FIGS. 3(   d   1 ) and  3 ( d   2 ), the manifold port apertures  2130  in the rotating cylinder  2100 , just prior to being covered back up by the reciprocating piston  2210 , line up primarily with the some of the frusto-pyramidal shaped slots  1350  in the manifold assembly  1300 , allowing intake air to fill the rotating cylinder  2100 . The intake air may be supplied by a supercharger and/or turbocharger, or by other methods well known in the art. 
     5. Operation of Further Embodiments 
       FIGS. 5(   a   1 )- 5 ( d   2 ) illustrate a second embodiment of the present invention. The figures describe a dual combustion chamber, two piston engine configuration of the present invention arranged in a coaxial and tandem manner over one complete piston cycle, or one-half of a full cylinder rotation, the cylinder rotation being counterclockwise. 
     One advantage of this embodiment is that the forces created by the reciprocation of the piston assemblies can be dynamically balanced by having the two reciprocating piston assemblies reciprocate in opposite directions. 
     As shown in  FIGS. 5(   a   1 )- 5 ( d   2 ), the two reciprocating piston assemblies  2200  are configured as previously described herein and are arranged along a single axis and in a tandem manner. Each of the reciprocating piston assemblies  2200  are set in the same orientation. The two left-most cylindrical cam components  1200  and  1201  would, however, be shifted in phase from the two right-most cylindrical cam components  1200  and  1201  to force the second reciprocating piston  2210  to reciprocate in exact opposition to the motion of the first reciprocating piston  2210 . 
       FIGS. 5(   a   1 ) and  5 ( a   2 ) show a starting position of the rotating cylinder assembly  2000 , with the left reciprocating piston  2210  at TDC and the right reciprocating piston  2210  at BDC. 
       FIGS. 5(   b   1 ) and  5 ( b   2 ) show the relative position of the rotating cylinder assembly  2000  after 45 degrees of rotation, with the left reciprocating piston  2210  moving rightward toward the other reciprocating piston assembly  2200  from TDC toward BDC due to its combustion phase and the right reciprocating piston  2210  moving leftward toward the other reciprocating piston assembly  2200  from BDC toward TDC. 
       FIGS. 5(   c   1 ) and  5 ( c   2 ) show the relative position of the rotating cylinder assembly  2000  after 90 degrees of rotation, positioning the left piston  2210  at BDC and the right piston  2210  at TDC. 
       FIGS. 5(   d   1 ) and  5 ( d   2 ) show the relative position of the rotating cylinder assembly  2000  after 135 degrees of rotation, with the left reciprocating piston  2210  moving leftward away from the other reciprocating piston assembly  2200  from BDC toward TDC and the right reciprocating piston  2210  moving rightward away from the other reciprocating piston assembly  2200  from TDC toward BDC due to its combustion phase. This embodiment is dynamically balanced and has no significant side loads on the pistons, unlike modern internal combustion engines, and has four power strokes per cylinder revolution, thereby providing very smooth engine power. 
     Another embodiment of the present invention is illustrated in  FIGS. 6(   a   1 )- 6 ( d   2 ). This embodiment has a single rotating cylinder assembly  2000 , two reciprocating piston assemblies  2200 , and a single combustion chamber. The figures feature a single rotating cylinder assembly  2000  and opposed reciprocating piston assemblies  2200 , where the reciprocating piston assemblies  2200  are the reciprocating piston assemblies previously disclosed herein. Further, the reciprocating piston assemblies  2200  are opposed in a mirrored fashion. The space between the reciprocating pistons  2210  forms a single combustion chamber. The mirroring of the second reciprocating piston assembly  2200  (the reciprocating piston assembly  2200  on the right hand portion of the images) provides cylindrical cam components  1200  and  1201  disposed about the second reciprocating piston assembly  2200  which are shifted in phase from the cylindrical cam components  1200  and  1201  disposed about the first reciprocating piston assembly  2200  (the reciprocating piston assembly  2200  on the left hand portion of the images), forcing the second reciprocating piston assembly  2200  to reciprocate in exact opposition to the motion of the first reciprocating piston assembly  2200 .  FIGS. 6(   a   1 )- 6 ( d   2 ) illustrate the operation of such a single cylinder, opposed piston engine configuration of the present invention over one complete piston cycle, or one-half of a full cylinder rotation, the cylinder rotation being counterclockwise. Similar to the embodiment described in  FIGS. 5(   a   1 )- 5 ( d   2 ), the present embodiment also results in dynamically balanced forces. 
       FIGS. 6(   a   1 ) and  6 ( a   2 ) show a starting position of the rotating cylinder assembly  2000 , with the reciprocating piston assemblies  2200  at TDC. 
       FIGS. 6(   b   1 ) and  6 ( b   2 ) show the relative position of the rotating cylinder assembly  2000  and reciprocating piston assemblies  2200  after 45 degrees of rotation, with both reciprocating pistons  2210  moving in opposite directions from their respective TDC positions toward their respective BDC positions due to the engine&#39;s combustion phase. 
       FIGS. 6(   c   1 ) and  6 ( c   2 ) show the relative position of the rotating cylinder assembly  2000  and reciprocating piston assemblies  2200  after 90 degrees of rotation, positioning the reciprocating pistons  2210  at BDC. 
       FIGS. 6(   d   1 ) and  6 ( d   2 ) show the relative position of the rotating cylinder assembly  2000  and reciprocating piston assemblies  2200  after 135 degrees of rotation, with both reciprocating pistons  2210  moving toward one another from their respective BDC positions toward their respective TDC positions. 
       FIGS. 7(   a   1 )- 7 ( h   2 ) illustrate another embodiment of the present invention. The figures describe a single cylinder dual opposed piston engine configuration. This embodiment utilizes two of the previously disclosed single cylinder opposed piston engine configurations, arranged in a coaxial and tandem but rotated manner. The figures illustrates the operation of one embodiment of the engine over one complete piston cycle, or one-half of a full cylinder rotation, the cylinder rotation being counterclockwise. 
     Each side of the rotating cylinder assembly  2000  has two sets of manifold port apertures  2130  formed near the end of each reciprocating piston  2210  and fuel injection port apertures  2120  between the two sets of manifold port apertures  2130  in communication with the combustion chamber. In one particular embodiment of this general engine type, each set of manifold port apertures  2130  may be responsible for either the intake or air only or the exhausting of air only. In such an embodiment, the reciprocating pistons  2210  cover and uncover their respective manifold port apertures  2130  during engine operation allowing air passages to close and open, respectively to control the flow of intake or exhaust gasses. This configuration not only allows for effective exhaust scavenging, but also permits independent, asymmetric timing of the intake and exhaust ports, and is presumed to be more efficient in scavenging exhaust, pressurizing intake air, and avoiding unnecessary and inefficient mixing of the two. Accordingly, each of the manifold assemblies  1300  may be responsible for handling either intake or exhaust, but not both. 
     Another unique aspect to this particular embodiment of the invention over the previously described embodiments is the shape and configuration of the cylindrical cam components  1200  and  1201 . One example of this embodiment may use another cylindrical cam component  1203  between the two sets of reciprocating piston assemblies  2200 . Cylindrical cam component  1203  may have two curvilinear surfaces opposite each, each of which interacts with barrel cam rollers  2220 . Another difference is that the phasing (the variation in where the peaks of one component rise and the valleys of the opposing component fall) of the cylindrical cam components for each cylinder may be arranged so that the manifold port apertures  2130  responsible for exhausting air open before the manifold port apertures  2130  responsible for air intake open and close before its intake manifold port apertures close. Instead of adjusting the phasing to accomplish this asymmetric timing, other embodiments may position the manifold port apertures  2130  at different positions relative to the reciprocating pistons  2210  such that the manifold ports  2130  responsible for exhaust open first after combustion relative to the manifold ports  2130  responsible for intake. This asymmetric timing makes it possible to utilize superchargers and/or turbochargers to enhance engine efficiency, and some embodiments take advantage of this possibility and do use superchargers, turbochargers, or both. The asymmetric timing further increase efficiency beyond the possibility of using superchargers, turbochargers, or both because: if the exhaust ports open before the intake ports, energy in the exhaust gases can be more effectively recovered by a turbocharger; if the exhaust ports close before the intake ports, the cylinder can be more effectively supercharged. 
     To provide the asymmetric timing while preserving the dynamic balance, one side of the rotating cylinder assembly  2000  has the manifold port apertures  2130  responsible for air intake on its inner end, while the other side of the rotating cylinder assembly  2000  has the manifold port apertures  2130  responsible for air intake on its outer end, with the mass and motion of the outer reciprocating piston assembly  2200  completely counteracted by the mass and motion of the inner reciprocating piston assembly  2200  on the opposing cylinder. In this configuration, the mass and motion of the remaining two reciprocating piston assemblies  2200  furthermore counteract each other. This results in an engine that has asymmetric timing and is yet completely dynamically balanced. 
     Despite the advantages of the above described embodiment with respect to asymmetric timing, other embodiments of this general engine type may have each set of manifold port apertures  2130  responsible for both the intake and exhaust of air. 
       FIGS. 7(   a   1 ) and  7 ( a   2 ) show a starting position of the rotating cylinder assembly  2000 , with the reciprocating piston assemblies  2200  on the left at approximately TDC and with reciprocating piston assemblies  2200  on the right at approximately BDC and the associated manifold port apertures  2130  open. 
       FIGS. 7(   b   1 ) and  7 ( b   2 ) show the relative position of the rotating cylinder assembly  2000 , reciprocating piston assemblies  2200 , and manifold port apertures  2130  after 22.5 degrees of rotation due to the combustion phase of the left side of the rotating cylinder assembly  2000 , with the left reciprocating piston assemblies  2200  moving away from one another and the right two reciprocating piston assemblies  2200  moving toward one another. Due to the phasing of the cylindrical cam components  1200  and  1201  disposed about each reciprocating piston assembly, where the cylindrical cam components on the left of each piston assembly are shifted approximately 7.5 degrees counterclockwise and the cylindrical cam components on the right of each piston assembly are shifted approximately 7.5 degrees clockwise, the reciprocating piston assemblies  2200  on the left in each cylinder will be moving at equal and opposite directions and the reciprocating piston assemblies  2200  on the right in each cylinder will be moving at equal and opposite directions. In this position, the right-most reciprocating piston assembly  2200  is covering its manifold port apertures  2130  and its corresponding opposing reciprocating piston assembly  2200  is still allowing its manifold port apertures  2130  to be uncovered so that pressurized intake air can be added to the space inside the rotating cylinder  2100 . 
       FIGS. 7(   c   1 ) and  7 ( c   2 ) show the relative position of the rotating cylinder assembly  2000 , reciprocating piston assemblies  2200 , and manifold port apertures  2130  after 45 degrees of rotation due to the combustion phase of the left side of the rotating cylinder assembly  2000 , with the left two reciprocating piston assemblies  2200  moving away from one another and the right two reciprocating piston assemblies  2200  moving toward one another. 
       FIGS. 7(   d   1 ) and  7 ( d   2 ) show the relative position of the rotating cylinder assembly  2000 , reciprocating piston assemblies  2200 , and manifold port apertures  2130  after 67.5 degrees of rotation due to the combustion phase of the left side of the rotating cylinder assembly  2000 , with the left two reciprocating piston assemblies  2200  moving away from one another approaching BDC and the right two reciprocating piston assemblies  2200  moving toward one another approaching TDC. In this position, the left-most reciprocating piston assembly  2200  is covering manifold port apertures  2130  and its corresponding opposing reciprocating piston assembly  2200  is now allowing its manifold port apertures  2130  to be uncovered so the exhaust gases can be effectively scavenged. 
       FIGS. 7(   e   1 ) and  7 ( e   2 ) show the relative position of the rotating cylinder assembly  2000 , reciprocating piston assemblies  2200 , and manifold port apertures  2130  after 90 degrees of rotation, with the left reciprocating piston assemblies  2200  at approximately BDC and its respective manifold port apertures  2130  open, and with the reciprocating piston assemblies  2200  on the right at approximately TDC. 
       FIGS. 7(   f   1 ) and  7 ( f   2 ) show the relative position of the rotating cylinder assembly  2000 , reciprocating piston assemblies  2200 , and manifold port apertures  2130  after 112.5 degrees of rotation due to the combustion phase of the right side of the rotating cylinder assembly  2000 , with the left two reciprocating piston assemblies  2200  moving toward one another and the right two reciprocating piston assemblies  2200  moving away from one another. In this position, the right reciprocating piston assembly  2200  in the left side of the rotating cylinder assembly  2000  is covering its manifold port apertures  2130  and its corresponding opposing reciprocating piston assembly  2200  is still allowing its manifold port apertures  2130  to be uncovered so that pressurized intake air can be added to the space inside rotating cylinder assembly  2000 . 
       FIGS. 7(   g   1 ) and  7 ( g   2 ) show the relative position of the rotating cylinder assembly  2000 , reciprocating piston assemblies  2200 , and manifold port apertures  2130  after 135 degrees of rotation due to the combustion phase of the right side of the rotating cylinder assembly  2000 , with the left two reciprocating piston assemblies  2200  moving toward one another and the right two reciprocating piston assemblies  2200  moving away from one another. 
       FIGS. 7(   h   1 ) and  7 ( h   2 ) show the relative position of the rotating cylinder assembly  2000 , reciprocating piston assemblies  2200 , and manifold port apertures  2130  after 157.5 degrees of rotation due to the combustion phase of the right side of the rotating cylinder assembly  2000 , with the left two reciprocating piston assemblies  2200  moving toward one another and the right two reciprocating piston assemblies  2200  moving away from one another. In this position, the left reciprocating piston assembly  2200  on the right side of rotating cylinder assembly  2000  is covering manifold port apertures  2130  and its corresponding opposing reciprocating piston assembly  2200  is now allowing its manifold port apertures  2130  to be uncovered so the exhaust gases can be effectively scavenged. 
     The specific angles and timing depend on the stationary cylindrical cam component geometries and intake and exhaust port sizes and locations; the above description is intended solely to illustrate the concepts of the invention. 
     Although the preferred embodiment engine of the present invention has the same total number of pistons as a conventional four cylinder in-line engine, for a comparable power output the mean piston velocity is substantially reduced, since each piston travels a shorter distance. 
       FIGS. 9(   a   1 )- 9 ( h   2 ) illustrate another embodiment of the present invention. The figures describe a single cylinder opposed piston engine configuration. This embodiment is similar to the embodiment depicted in  FIGS. 7(   a   1 )- 7 ( h   2 ), but combines the center two reciprocating piston assemblies  2200  from that previously disclosed embodiment into a single center reciprocating piston assembly  2280  with a single longer piston and only one set of barrel cam rollers. This center reciprocating piston assembly  2280  thus interacts with both the left and right combustion chambers. The figures illustrates the operation of such an embodiment of the engine over one complete piston cycle, or one-half of a full cylinder rotation, the cylinder rotation being counterclockwise. 
     Each side of the rotating cylinder assembly  2000  has two sets of manifold port apertures  2130  formed near the BDC position of each reciprocating piston  2210  and fuel injection port apertures  2120  between the two sets of manifold port apertures  2130  communicating with the combustion chamber. In one particular embodiment of this general engine type, each set of manifold port apertures  2130  may be responsible for either the intake of air only or the exhausting of air only. This configuration not only allows for effective exhaust scavenging, but permits independent, asymmetric timing of the intake and exhaust ports, and is presumed to be more efficient in scavenging exhaust, pressurizing intake air, and avoiding unnecessary and inefficient mixing of the two. 
     To provide appropriate intake and exhaust timing, one side of the rotating cylinder assembly  2000  has the manifold port apertures  2130  responsible for air intake on its inner end, while the other side of the rotating cylinder assembly  2000  has the manifold port apertures  2130  responsible for air intake on its outer end, with the mass and motion of the two outer reciprocating piston assemblies  2200  completely counteracted by the mass and motion of the center reciprocating piston assembly  2280 . Such manifold and piston arrangements result in an engine that has asymmetric intake and exhaust timing and is yet completely dynamically balanced. 
     Despite the advantages of the above described embodiment with respect to asymmetric timing, other embodiments of this general engine type may have each set of manifold port apertures  2130  responsible for both the intake and exhaust of air. 
       FIGS. 9(   a   1 ) and  9 ( a   2 ) show a starting position of the rotating cylinder assembly  2000 , with the left reciprocating piston assembly  2200  at TDC, with the center reciprocating piston assembly  2280  at its left-most position, and with the right reciprocating piston assembly  2200  at BDC. In this position, the right two sets of manifold port apertures  2130  in the rotating cylinder  2100  are uncovered and lined up with some of the frusto-pyramidal shaped slots  1350  in the right two manifold assemblies  1300 , so exhaust gases are allowed to escape through the right apertures and intake gases are allowed to enter through the left apertures. 
       FIGS. 9(   b   1 ) and  9 ( b   2 ) show the relative position of the rotating cylinder assembly  2000 , reciprocating piston assemblies  2200  and  2280 , and manifold port apertures  2130  after 22.5 degrees of rotation due to the combustion phase of the left side of the rotating cylinder assembly  2000 , with the outer two reciprocating piston assemblies  2200  moving leftward and the center reciprocating piston assembly  2280  moving rightward. In this position, the manifold port apertures  2130  in the rotating cylinder  2100  to the right of the center reciprocating piston assembly  2280  are uncovered and lined up with some of the frusto-pyramidal shaped slots  1350  in the manifold assembly  1300  to the right of the center reciprocating piston  2280 , so that pressurized intake air can be added to the space inside the rotating cylinder  2100 . 
       FIGS. 9(   c   1 ) and  9 ( c   2 ) show the relative position of the rotating cylinder assembly  2000 , reciprocating piston assemblies  2200  and  2280 , and manifold port apertures  2130  after 45 degrees of rotation due to the combustion phase of the left side of the rotating cylinder assembly  2000 , with the outer two reciprocating piston assemblies  2200  moving leftward and the center reciprocating piston assembly  2280  moving rightward. 
       FIGS. 9(   d   1 ) and  9 ( d   2 ) show the relative position of the rotating cylinder assembly  2000 , reciprocating piston assemblies  2200  and  2280 , and manifold port apertures  2130  after 67.5 degrees of rotation due to the combustion phase of the left side of the rotating cylinder assembly  2000 , with the outer two reciprocating piston assemblies  2200  moving leftward toward their left most positions and the center reciprocating piston assembly  2280  moving rightward toward its rightmost position. In this position, the manifold port apertures  2130  in the rotating cylinder  2100  to the left of the center reciprocating piston assembly  2280  are uncovered and lined up with some of the frusto-pyramidal shaped slots  1350  in the manifold assembly  1300  to the left of the center reciprocating piston  2280 , so the exhaust gases from that combustion chamber can be effectively scavenged. 
       FIGS. 9(   e   1 ) and  9 ( e   2 ) show the relative position of the rotating cylinder assembly  2000 , reciprocating piston assemblies  2200  and  2280 , and manifold port apertures  2130  after 90 degrees of rotation, with the left reciprocating piston assembly  2200  at BDC, with the center reciprocating piston assembly  2280  at its right-most position, and with the right reciprocating piston assembly  2200  at TDC. In this position, the left two sets of manifold port apertures  2130  in the rotating cylinder  2100  are uncovered and lined up with some of the frusto-pyramidal shaped slots  1350  in the left two manifold assemblies  1300 , so exhaust gases are allowed to escape through the right apertures and intake gases are allowed to enter through the left apertures. 
       FIGS. 9(   f   1 ) and  9 ( f   2 ) show the relative position of the rotating cylinder assembly  2000 , reciprocating piston assemblies  2200  and  2280 , and manifold port apertures  2130  after 112.5 degrees of rotation due to the combustion phase of the right side of the rotating cylinder assembly  2000 , with the outer two reciprocating piston assemblies  2200  moving rightward and the center reciprocating piston assembly  2280  moving leftward. In this position, the left-most manifold port apertures  2130  in the rotating cylinder  2100  are uncovered and lined up with some of the frusto-pyramidal shaped slots  1350  in the left-most manifold assembly  1300 , so that pressurized intake air can be added to the space inside the rotating cylinder  2100 . 
       FIGS. 9(   g   1 ) and  9 ( g   2 ) show the relative position of the rotating cylinder assembly  2000 , reciprocating piston assemblies  2200  and  2280 , and manifold port apertures  2130  after 135 degrees of rotation due to the combustion phase of the right side of the rotating cylinder assembly  2000 , with the outer two reciprocating piston assemblies  2200  moving rightward and the center reciprocating piston assembly  2280  moving leftward. 
       FIGS. 9(   h   1 ) and  9 ( h   2 ) show the relative position of the rotating cylinder assembly  2000 , reciprocating piston assemblies  2200  and  2280 , and manifold port apertures  2130  after 157.5 degrees of rotation due to the combustion phase of the right side of the rotating cylinder assembly  2000 , with the outer two reciprocating piston assemblies  2200  moving rightward toward their right-most positions and the center reciprocating piston assembly  2280  moving leftward toward its left-most position. In this position, the right-most manifold port apertures  2130  in rotating cylinder  2100  are uncovered and lined up with some of the frusto-pyramidal shaped slots  1350  in the right-most manifold assembly  1300 , so the exhaust gases from that combustion chamber can be effectively scavenged. 
     The specific angles and timing depend on the stationary cylindrical cam component geometries and intake and exhaust port sizes and locations; the above description is intended solely to illustrate the concepts of the invention. 
     Compared to a current state-of-the-art production four cylinder in-line engine having comparable performance, the engine of the present invention provides substantial improvements in installation suitability, the reduction of friction losses, and the elimination of vibration. Friction due to lateral forces on the pistons is greatly reduced by this design, since there are no piston rods imparting such side loads into the pistons. Furthermore, the engine of the present invention can be totally dynamically balanced. The overall volume of the engine of the present invention represents an approximately 40% reduction over a four cylinder in-line engine, with a corresponding 30% reduction in weight, and a 50% reduction in frontal area. 
     The above is a detailed description of particular embodiments of the invention. It is recognized that departures from the disclosed embodiments may be within the scope of this invention and that obvious modifications will occur to a person skilled in the art. It is the intent of the applicant that the invention include alternative embodiments known in the art that perform the same functions as those disclosed. This specification should not be construed to unduly narrow the full scope of protection to which the invention is entitled. 
     The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the following claims are intended to include any structure, material, or acts for performing the functions in combination with other claimed elements as specifically claimed.