Abstract:
A rotary engine includes separate chambers for receiving pressurized air and fuel. An air chamber stories pressurized air that is routed into a combustion chamber to be mixed with fuel for combustion to drive a piston. The combustion chamber is forced open during a firing cycle to allow expanding gases into a piston chamber. A valve door serves as a base against which the expanding gases react to force a piston in a forward direction. The piston is coupled to a crank shaft which may in turn be coupled to a transmission or other power drive device to harness energy created by the turning crankshaft. A lifter includes a gear that rotates to raise and lower the valve door such that it moves towards and away from the crankshaft to optimize the amount of energy that is directed against the piston. Through series of multiplier gears, the amount of movement necessary to lift the door is minimal.

Description:
There are no related patent applications. 
   This patent application did not receive any federal research and development funding. 
   BACKGROUND OF THE INVENTION 
   The invention generally relates to a rotary piston engine. More particularly, the invention relates to a rotary piston engine that includes an air chamber for storing pressurized air that is routed into a separate combustion chamber for ignition purposes. The engine includes a housing that surrounds at least one rotor coupled to a piston for driving a shaft that may be coupled to a drive assembly for harnessing rotational energy produced by the rotor. A movable valve door provides a base against which expanding gases react to force the piston in a forward direction. The valve door is drawn away from the shaft to allow the piston to pass-by to complete a revolution. 
   Internal combustion engines are typically referred to as either a reciprocating piston engine or a rotary piston engine. Reciprocating piston engines use crank gears to translate movement of pistons into a rotary motion. The use of crank gears in a rotary piston engine is unnecessary since the piston performs a rotary motion during operation. 
   The most popular rotary engine, the Wankle rotary engine, includes a piston having a cross-section similar to a triangle and rotates in a uniquely shaped cylinder. Because of the unique shape of the cylinder, it encounters sealing problems that result in high fuel consumption. Most known rotary piston engines are complex and require high production and maintenance costs. 
   It should be noted that the discussion of the rotary engine in the present invention is not limited to internal combustion engines. The present invention may be modified to be powered by air, geothermal energy or the like. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention is a rotary engine that includes separate air and fuel combustion chambers. Pressurized air is pumped into an air chamber that stores the air until completion of a firing cycle. The pressurized air is then routed into a combustion chamber and mixed with fuel to be combusted. Expanding gases from the combustion chamber are directed into a cylinder defined by a housing. A movable valve door provides a surface against which the gases react to force a piston and rotor around a crankshaft. The crankshaft may be coupled to a drive assembly for use in harnessing the energy produced by the engine. 
   The rotary engine includes a housing that defines a working cylinder in which a piston and rotor rotate. The piston and rotor are coupled to a crankshaft. A valve door is operablely disposed within the cylinder such that it is withdrawn from the cylinder to allow the piston to pass between the rotor and the valve door to complete a revolution. A lifter comprises a gear that is rotated in opposite directions to raise and lower the valve door such that it moves towards and away from the crankshaft to optimize the amount of energy that is directed against the piston. Through series of multiplier gears, the amount of movement necessary to lift the valve door is minimal. 
   It is an object of the invention to provide a rotary engine that has separate air pressurizing and fuel/air mixing chambers. 
   It is a further object of the invention to provide a rotary engine that includes a novel lifter mechanism for withdrawing a valve door from the working cylinder of the piston. 
   It is an additional object of the invention to provide a rotary engine that is high torque engine having greater fuel efficiency and less energy losses than rotary engines of the past. 
   It is another object of the invention to provide a simplified rotary engine that is less costly to produce and maintain while maximizing an amount of energy realized during combustion of fuel. 
   Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned from practicing the invention. The objects and advantages of the invention will be obtained by means of instrumentalities in combinations particularly pointed out in the appended claims. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
       FIG. 1A  is a front elevation view of the engine of the present invention and having protective shielding installed. 
       FIG. 1B  is a side elevation view of the engine shown in FIG.  1 A. 
       FIG. 2A  is a right side elevation view of the engine shown with the protective shielding removed. 
       FIG. 2B  is a front elevation view of the engine shown in FIG.  2 A. 
       FIG. 2C  is a right side elevation view of the engine shown with a flywheel and ignition coil removed. 
       FIG. 2D  is a front elevation view of the engine shown in FIG.  2 C. 
       FIG. 2E  is a left side elevation view of the engine shown in FIG.  2 C. 
       FIG. 3A  is a front elevation view of the engine shown with a timing system and a front rotor plate removed. 
       FIG. 3B  is a back elevation view of the engine shown in  FIG. 3A  with an air compressor and back plate removed. 
       FIG. 3C  is a right side elevation view of the engine shown in  FIG. 3A  with an outer center rotor case and the head for the combustion chamber removed. 
       FIG. 3D  is a left side elevation view of FIG.  3 C. 
       FIG. 4A  is an enlarged front elevation view of the valve system. 
       FIG. 4B  is an enlarged back elevation view of the valve system. 
       FIG. 4C  is a top plan view of the valve system shown in  FIGS. 4A and 4B . 
       FIG. 4D  is a left side elevation view of the cam gear system. 
       FIG. 4E  is a front elevation view of the lifter and cam track shown in FIG.  4 D. 
       FIG. 5A  is an exploded view of the rotor and rotor case components taken from the side. 
       FIG. 5B  is a partial exploded view of the rotor and rotor case components shown in FIG.  5 A. In this Figure, the rotor seal vane attaches to the rotor. 
       FIG. 5C  is an exploded view of the valve door shown in FIG.  5 B. 
       FIG. 5D  is an exploded view of the piston assembly. 
       FIG. 5E  is an exploded view of the rotor and the rotor seal vanes. 
       FIG. 5F  is an exploded view of the vane seal for the top of the piston. 
       FIG. 5G  is an enlarged view of a seal for sealing the outer rotor case near where the valve door operates. 
       FIGS. 6A through 6D  depict the timing rotation of the piston and valve system including valve door during one rotation of operation. 
       FIG. 7  an elevation view of the compression pump. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1A  shows the engine of the present invention. The engine  1  comprises an outer casing including a rotor case  8 , a flywheel housing  36  and a valve cover  5 . Each of these protects internal working parts by preventing foreign debris or materials from coming into contact with the internal workings of the engine. The various casings, housings and covers may be attached by known means such as bolts, screws, clips, fasteners or other such securing means. 
   In this embodiment, the engine  1  is shown as a gasoline type of engine. However, it may be noted that the engine may be modified to be driven with air, diesel, battery or steam. One of ordinary skill in the art can readily recognize that modifications may be undertaken to allow the engine to be driven by various propellants or forms of energy. 
   The upper portion of the engine comprises an air chamber  4  defined by head  63 . Air flows into air chamber  4  through air intake vent  14  for use in the combustion process. Typically head  63  is constructed of a light-weight metal such as cast steel or aluminum and may include an inner liner of composite material for preventing expansion of the head when pressure within the air chamber  4  is increased. Head bolts  49  secure the head  63  to the engine  1  and allow access to the inner air chamber for maintenance or other such reasons. 
   A combustion chamber  13  is provided opposite the air chamber  4  for combustion of fuels. Fuel is injected into the combustion chamber  13  along with pressurized air provided from the air chamber  14  before combustion. A spark plug  3  electronically controls the firing or combustion of the pressurized fuel within the combustion chamber  13 . The unique design of the engine  1  separates the operation of pressurizing air and fuel into different chambers. In other engines, this step is achieved by pressurizing a fuel/air mixture within a piston chamber by compressing the fuel/air mixture with the piston. A head  64  defines the combustion chamber  13  and includes bolts  49  for allowing access to the combustion chamber for maintenance purposes. 
   A lower portion of the engine  1  includes an oil reservoir  18  for storing a lubricant that is used to reduce internal friction and wear of the moving parts. Bolts  53  secure the engine case to prevent access to the internal workings of the engine. These bolts  53  may be removed to allow maintenance of the internal workings as necessary. Mounting bolts  50  are provided for securing the engine  1  in a desired location. An exhaust port  16  expels combusted gases from the interior of the engine. 
   In  FIG. 1B , the engine is shown from the side. A dipstick  9  is provided for measuring the level of lubricant necessary for operating the engine. The dipstick  9  may include marks that indicate the level of lubricant within the oil reservoir  18 . 
   A throttle control  11  controls the amount of air that is drawn into air chamber  4  for proper mixture of the fuel-to-air ratio. By controlling oxygen that is fed into the air chamber  4 , the fuel-to-air ratio may be manipulated to control the revolutions of the piston. That is to say, the amount of pressure exerted onto the rotor may be controlled by manipulating the airflow into the air chamber  4 . 
   A fuel injector  12  controls the amount of fuel flowing into the combustion chamber  13 . The fuel injector  12  is controlled by a microprocessor, not shown. A fuel pump, not shown, pressurizes the fuel such the injector  12  may open and close in a rapid succession to create an aerosol spray of fuel that is supplied to the combustion chamber  13 . 
   Now turning to  FIGS. 2A through 2E , that show the various views of the engine  1  with the outer protective casings removed. A compression pump  10  communicates with the air intake vent  14  to draw in air, compress it and force air into air chamber  4 . The compression pump  10  is discussed in greater detail in FIG.  7 . In one embodiment, the compression pump  10  is coupled to the crankshaft  2  and driven by the engine  1 . However, it can be easily recognized that other compression pumps or compressors may be electrically driven to supply pressurized air to the air chamber. A pressure feed tube  54  is provided for transporting pressurized air from the compression pump  10  to the air chamber  4 . 
   A back rotor plate  62  and front rotor plate  61  provide support for the piston rotor  42 , shown in FIG.  3 A. The rotor plates  61 ,  62  provide a sealed lubricating chamber in which piston rotor  42  travels around. 
   A timing belt  40  is driven by the crankshaft  2  to control the timing of the firing and pressurized air inflow sequences. The timing belt  40  overlaps both timing gears  20 B and  20 A. Timing gear  20 B is coupled to the crankshaft  2  for driving the timing belt  40  and causing it to drive timing gear  20 A. Timing gear  20 A is coupled to camshaft  24  for controlling the operation of camshaft  24 . Camshaft  24  is retained by bolts  52 . 
   An ignition coil  7  is coupled to spark plug  3  for providing an electric pulse thereto. The ignition coil  7  generates an electric pulse as the flywheel  65  passes near the coil  7  in a known fashion. The ignition coil  7  is secured by bolts  51 . 
   Flywheel  65  stores and provides rotational energy for driving the engine. The flywheel  65  comprises magnets that provide a magnetic pulse to the ignition coil  7  as the flywheel  65  passes near the coil  7 . This magnetic pulse is relayed from the ignition coil  7  to the spark plug  3  for combustion purposes. A crankshaft nut  6  secures the flywheel  65  and the crankshaft  2 . 
   Now turning to  FIG. 2C , an idle pulley adjustment device  44  is provided for adjusting tension on the timing belt  40 . This device  44  exerts constant pressure onto the timing belt  40  to prevent it from slipping from gears  20 A and  20 B. 
   An oil pump  43  is also driven by timing belt  40  to cause pressurized lubricant to be forced through a series of lubricating orifices, not shown. The oil pump  43  draws oil from the oil reservoir  18  and routes it to specific areas within the engine  1 . A moon key  41  is inserted into an opening in the crankshaft  2  for ensuring that the flywheel  65  is maintained in a proper relationship to crankshaft  2 . 
     FIG. 3A  shows a front elevation view of the internal workings of the engine  1 . In this view, the timing system and a front rotor plate is removed. Motor mount  15  comprises the motor mount casing to provide a stable support that holds the engine in a fixed position during operation. Piston  38  attaches to rotor  42  to drive the rotor  42  in a circular manner. Rotor seal  58  is disposed between the piston  38  and rotor  42  to ensure proper sealing of the rotor  42  with the outer casing to prevent leakage of gases that drive the piston  38 . The rotor seal may comprise a composite, metal, rubber, fiberglass or other such known material. Both the piston  38  and the rotor  42  comprise a track or guide, not shown, for accepting the rotor seal  58 . 
   Valve door  29  moves towards and away from the crankshaft  2  to direct the flow of gases or other propellants towards the backside of the piston  38 . Thus, the valve door  29  provides a base against which the explosion of fuel reacts to propel the piston  38  in a forward direction. The valve door  29  also acts to prevent propellants from flowing in a wrong direction. The valve door  29  includes a valve rail  48  ensuring proper alignment of the valve door  29  as it is lifted away from the crankshaft  2  during a completed rotation of the rotor  42  and allowing the piston  38  to pass. 
   An exhaust check valve spring  32  maintains proper tension on the exhaust check valve  23  to prevent leakage of propellants from the combustion chamber  13 . The exhaust check valve  23  seals the combustion chamber and is forced open when combustion of the propellants occurs to allow the expanding gases to be directed into the rotor case to drive the piston  38 . An exhaust input  46  directs these expanding gases between the piston  38  and the valve door  29 . 
   Check valve spring  55  biases check valve  21  to allow pressured air to flow from air chamber  4  into combustion chamber  13  while preventing a back flow of gases and propellants from the combustion chamber  13  into air chamber  4 . Pressurized air conduit  35  directs air from the air chamber  4  into the combustion chamber  13 . 
   Valve rocker arm  31  attaches at one end to exhaust check valve  23  and at a second end to cam lobe  5  to control the opening and closing of the exhaust valve  23  to direct propellants against the piston  38 . Cam lobe  57  comprises the camshaft  24 . The cam lobe  57  controls the opening and closing of the exhaust check valve  23  in a known manner. 
   Lifter  25  controls opening and closing of the valve door  29 . The lifter  25  comprises a gear that is rotated in opposite directions to raise and lower the valve door  29  such that it moves towards and away from the crankshaft  2  to optimize the amount of energy that is directed against the piston  38 . Through series of multiplier gears  26  and  27 , the amount of movement necessary to lift the valve door  29  is minimal. That is to say, a maximum of 20 degrees of rotation of the cam  24  causes the valve door  29  to be lifted and lowered to complete one revolution of the piston  38 . 
   Air chamber check valve spring  33  prevents leakage of pressurized air from air chamber  4 . When the internal pressure of air chamber  4  exceeds a predetermined threshold, check valve  22  opens to allow pressurized air to flow from the air chamber  4  through conduit  35  into combustion chamber  13 . It should be noted that check valve  22  and check valve  23  are arranged such that only one can open at a given time. That is to say, both check valves  22  and  23  cannot be open at the same moment in time.  FIG. 4B  is an enlarged back elevation view of the valve system that more clearly depicts cam track  39 .  FIG. 4C  is an overhead plan view of the arrangement of parts in the valve system of  FIGS. 4A and 4B . Bearings, not shown are provided for securing camshaft  34  in place. 
     FIGS. 4D and 4E  show the cam gear system and arrangement of gears for actuating the various parts. In  FIG. 4D  rotation from cam shaft  24  is translated to cam track  39  and cam lobe connector  57 . Cam track  39  drives lifter  25  which connects to gear  26  via a common shaft. Lifter  25  drives gear  26 . Gear  26  is coupled to gear  27  via a second shaft to drive it. Therefore, gears  26  and  27  increase or multiple rotational movement of gear  25 . This rotational movement is translated into linear movement by gear track  28  for raising and lowering the valve door  29 , as previously discussed.  FIG. 4E  shows the arrangement of lifter  25  and cam track  39 . 
     FIG. 5A  is an exploded view of the rotor  42  and rotor case assembly. Front rotor plate  61  includes a valve track  30 . Back rotor plate  62  also includes a valve track  30 . These valve tracks operate as previously discussed to allow movement of the valve door  29  towards and away from the crankshaft  2 . Front and back rotor plates  61  and  62  connect to outer rotor case  56 . A pair of rotor seal vanes  58  is disposed against the rotor  2  to prevent gases from leaking between the rotor  2 , piston  38  and the housing, as previously discussed. Springs  59  are arranged at various locations on the rotor  2  to bias the vanes  58  towards the plates  61  and  62  to ensure a proper seal. 
   A seal vane  37  is provided for sealing between the valve door  29  and the rotor  42  to prevent leakage of gases therebetween. The arrangement of the seal vane  37  and valve door assembly is more clearly shown in FIG.  5 C.  FIG. 5B  is a partial exploded view of the rotor and rotor case components with the rotor seal vane  58  in place. 
     FIG. 5C  is an exploded view of the valve door assembly. The valve door  29  includes gear track  28  that couples to gear  27  as shown in the previous figures. A pair of valve rails  48  attach to sides of the valve door  29  by screws  47 . Seal vane  37  attaches to an inner or bottom portion of the valve door  29  via screws  45 . It should be noted that the valve door  29  includes a recess for accommodating the vane  37 . Springs  59  are disposed between the vane  37  and the recess of the valve door  29  as shown. These springs  59  force the vane  37  away from the valve door  29  to ensure a proper seal when the valve door  29  and rotor  42  meet. 
     FIG. 5D  shows the piston assembly. The vane seal  60  for the piston  38  is seated between the piston  38  and the outer rotor case  56 , shown in  FIG. 5A. A  pair of springs  67  are disposed against a pair of screws  66  that secure the piston  38  to the rotor  42 . The vane seal  60  prevents leakage of gases between the piston  38  and the outer rotor case  56 . Ends of the vane seal  60  contact the rotor vane seals  58  to seal the piston  38 . Piston  38  includes a lower extension that locks the piston  38  into the rotor  42 , as shown. The vane seal  60  includes recesses on either end as shown for accepting end caps  69  as shown in FIG.  5 F. As more clearly seen in  FIG. 5F , the rotor vane seals  58  include keys  68  for accepting seal  60 . Springs  70  are disposed between end caps  69  and seal  60 . The end caps  69  are seated in recesses within the seal  60 . 
     FIG. 5G  shows the outer rotor case seal  72  that seats within a recess provided in the outer rotor case  56 . A plurality of springs  71  are disposed between the recess and the seal  72 . Not shown are the input and output openings for depositing combusting fuel into the rotor casing  56  and exhausting spent fuel therefrom. 
     FIG. 5E  is an exploded view of the piston showing the rotor seal vanes  58  in relation to the piston  38 . Each rotor seal vane  58  includes a key  68  that mates with a lip on the piston  38  to ensure that each vane  58  moves in concert with the piston  38 . Causing the vanes  58  to move with the piston  38  prevents a buildup of internal friction between the rotor  38  and the vane  58 . 
     FIGS. 6A through 6D  show a timing cycle of operation for the piston and valve assembly. In  FIG. 6A , the piston  38  is shown at approximately 300 degrees into the operation cycle. The exhaust valve  23  is held open by the rocker arm  31  that is being operated by the cam lobe  57 . During the operating cycle, the air chamber  4  is being pressurized by the air pump  10  through pressure feed tube  54 . The valve  23  prevents port valve  22  from opening to allow the pressurized air to flow into the combustion chamber  13 . Air in front of the piston  38  is forced from the exhaust port  16  to prevent a build up of pressure in front of the piston  38 . 
   In  FIG. 6B , the piston  38  is shown at approximately 350 degrees. In this view, exhaust check valve  23  is forced shut by the biasing force of exhaust check valve spring  32  as controlled by the valve rocker arm  31  which is driven by cam lobe connector  57 . Pressure from the air chamber  4  forces the port valve  22  open allowing pressurized air to flow from the air chamber  4  into combustion chamber  13 . Check valve  21  is also forced open until pressure within each chamber becomes equalized. When pressure is normalized between the chambers, a biasing force from the springs  33  and  55  closes each valve  21  and  22 . 
   In  FIG. 6C , the piston  38  has completed one revolution and returns to zero degrees. The lifter  25  is already activated to open the valve door  29  preventing the rotor piston  38  from contacting it and becoming damaged. In other words, the valve door  29  moves away from the rotor  42  to allow the piston  38  to complete a cycle. At this time, all pressure created by combustion of the fuel has been expended and released. 
   In  FIG. 6D , the piston  38  is at approximately ten degrees. Valve door  29  has returned to its normal position and is shut. Fuel injector  12  injects fuel into the combustion chamber  13 . Check valve  23  is biased shut by spring  32  until fuel within the combustion chamber  13  is ignited. Upon ignition of the fuel, the valve  23  is forced open to allow expanding gases to flow from the combustion chamber  13  into the space between the valve door  29  and the piston  38 . The force from the expanding gases is exerted against the backside of the piston  38  causing it and the rotor  42 , as well as the crankshaft  2 , to rotate. During this process, spent fuel from the previous burning cycle is forced from the exhaust port  16 . 
     FIG. 7  is a plan view of the air compressor shown without a housing. An intake check valve  100  allows air to flow into the compressor while preventing it from flowing outward through the intake. An output port  101  directs compressed air from the compressor into the pressure feed tube  54  and connects thereto. An output check valve  102  allows air to be forced outward through output port  101  whilst preventing it from flowing from the air chamber  4  back into the compressor. 
   Piston  103  moves towards and away from the inner cam  112  that is sleeved onto the crankshaft  2 . Piston rod  104  connects to piston  103  for forcing the piston  103  towards or away from the outer cam lobe  111 . Roller pin  105  connects to the piston rod  104  to run along the outer perimeter of the outer cam lobe  111  to compress air. The compressor mounts to the engine via mounts  106  as shown in FIG.  2 A. 
   Piston rod track  107  includes a groove that prevents the roller pin.  105  from turning in an undesirable direction. The piston rod spring  108  maintains pressure between the piston  103  and the outer cam lobe  111 . It also forces the piston  103  towards the inner cam  112 . Head bolts  109  maintains the upper heads of the piston  103  in place and allows access for maintenance. Intake screen  110  prevents debris and foreign objects from entering intake check valve  100 . 
   It is to be understood that the invention is not limited to the exact construction illustrated and described above, but that various changes and modifications may be made without departing from the spirit and the scope of the invention as defined in the following claims.