Abstract:
A very simple four-cycle, multi-chamber rotary internal combustion engine that includes a hollow stator with inner surface formed by two concentric cylindrical surfaces which fluently transit one into the other via ramp surfaces, and a cylindrical rotor, having same radius as smaller concentric surface of the stator, with a vane-type pistons that can freely move in radial direction within radially made rectangular grooves in the rotor and having means permitting outer facets of the pistons to tightly contour the inner surface of the stator during rotation of the rotor is disclosed. The cavities within the stator made in the areas where the inner surface of the stator has the same radius as that of the rotor form combustion chambers, which connect to the working chamber formed between outer surface of the rotor and inner surface of the stator with bigger radius via the orifices ending within the portions of the ramp surfaces of the stator. Timely connections among combustion and working chambers during compression and power cycles are regulated by conventional valve system.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     Not Applicable  
       FEDERALLY SPONSORED RESEARCH  
       [0002]     Not Applicable  
       SEQUENCE LISTING OR PROGRAM  
       [0003]     Not Applicable  
       BACKGROUND OF THE INVENTION  
       [0004]     1. Field of the Invention  
         [0005]     The invention relates to internal combustion engines, in particular to true rotary engines in which the energy of combusted gases directly drives rotation of the rotor and whose working members rotate around an axle fixed on a rotor.  
         [0006]     2. Discussion of Prior Art  
         [0007]     The drawbacks of a conventional internal combustion engine, in which reciprocal movements of the pistons are translated into rotation of a crankshaft via special transduction means, are well known. The major ones are: 1) low efficiency coefficient due to losses on friction of slide between pistons and cylinders walls and transduction of reciprocal-to-rotational motion; 2) excessive vibrations due to imbalances in the whole piston—transduction mechanism—crancshaft system; 3) big weight. The real alternative to the conventional reciprocal internal combustion engine (CICE) is rotary internal combustion engine (RICE), in which the energy of expanding gasses directly drives the rotation of the shaft.  
         [0008]     Many models of RICE have been proposed and patented. The search of only full-text U.S. Patent Database (patents from 1976 to present) with the patent&#39;s title words query “(((rotary AND internal) AND combustion) AND engine)” resulted in 319 hits, of which about 80% represent new technical solutions. The data on technical testing of the acting prototypes for the most patented RICE models is not available. However, it seems that limited or questionable benefits offered by existing technical solutions of the RICE so far do not justify mass production of any of them, and replacement of the CICE. Most existing models apparently suffer either from excessive complexity translatable into high weight and cost of production or do not provide notable gains in the efficiency coefficient due to inability to reduce leak of gasses among working members. The most advanced model of RICE in terms of industrial elaboration is Wankel engine. The rotor in this type of engine has three convex facets and rotates eccentrically within cylindrical stator with peritrochoidal inner surface. However, this model still suffers from problems in pressurization of the combustion chamber, insufficient durability of compression elements, poor fuel efficiency especially at low loads and enhanced emission of carbohydrates.  
         [0009]     The present invention most closely relates to the vane-type RICE, in which the energy of combusted gasses drives rotation of the rotor via interaction with the vane(s) disposed on the rotor, and thereby is the most effective in terms of energy conversion efficiency. To create working chambers of variable volume required for performing gas compression and expansion cycles the prior arts took advantage of eccentric disposition of the rotor within cylindrical stator (U.S. Pat. No. 1,255,865, NPC  123 / 235 , February 1918; U.S. Pat. No. 2,511,441, NPC  123 / 235 , June 1950, U.S. Pat. No. 3,951,112, NPC  123 / 242 , April 1976; U.S. Pat. No. 3,955,540, NPC  418 / 260 , May 1976; U.S. Pat. No. 3,964,447, NPC  123 / 236 , June 1976; U.S. Pat. No. 4,422,419, NPC  123 / 235 , December 1983; U.S. Pat. No. 4,848,296, NPC  123 / 242 , July 1989; U.S. Pat. No. 6,247,443, NPC  123 / 229 , June 2001) or concentric disposition of the rotor within the stator having peritrochoid/ellipsoid-like (U.S. Pat. No. 4,018,191, NPC  123 / 243 , April 1977; U.S. Pat. No. 4,667,468, NPC  123 / 248 , May 1987; U.S. Pat. No. 5,277,158, NPC  123 / 243 , January 1994; U.S. Pat. No. 6,539,913, NPC  123 / 231 , April 2003) or specially shaped (U.S. Pat. No. 1,792,026, NPC  123 / 235 , February 1931; U.S. Pat. No. 4,515,123, NPC  123 / 222 , May 1985; U.S. Pat. No. 5,423,297, NPC  123 / 213 , June, 1995; U.S. Pat. No. 6,070,565, NPC  123 / 231 , June 2000) inner surface together with the vanes movable in radial slots within the rotor while sealingly engaged with the surface of the stator.  
         [0010]     However in many types of vane-type rotary engines the structure is complex due to many components and tangled intrinsic system of gas conduits, and thus manufacturing costs may become high. The reliability and durability of gas sealing mechanisms in existing technical solutions also remains the matter of concern. Thus, simple and yet reliable model of RICE that would attract manufactures attention still remains a priority.  
       SUMMARY  
       [0011]     A very simple four-cycle, multi-chamber rotary internal combustion engine that includes a hollow stator with inner surface formed by two concentric cylindrical surfaces which fluently transit one into the other via ramp surfaces, and a cylindrical rotor, having same radius as smaller concentric surface of the stator, with a vane-type pistons that can freely move in radial direction within radial rectangular grooves in the rotor and having means allowing their outer facet to tightly contour the inner surface of the stator during rotation of the rotor is disclosed. The cavities within the stator made in the areas where the inner surface of the stator has the same radius as that of the rotor form combustion chambers, which connect to the working chambers formed between outer surface of the rotor and inner surface of the stator with bigger radius via the orifices ending within the portions of the ramp surfaces of the stator. Timely connections among combustion and working chambers during compression and power cycles are regulated by a conventional valve system. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     Various other objects, features and attendant advantages of the present invention will be more fully appreciated and the same becomes better understood from the following detailed description when considered in connection with the accompanying drawings in which like reference characters designate like or corresponding parts throughout the several views and wherein:  
         [0013]      FIG. 1  shows a prospective view of the assembled engine of the present invention. The arrows A, B and C represent different gas flows as they are related to specific parts of the engine shown in this and other figures.  
         [0014]      FIG. 2  shows an exploded perspective view of the engine. Not to overload the image the valves are not depicted.  
         [0015]      FIG. 3  shows a transverse section of the engine&#39;s stator taken in 3—3 plane in  FIG. 2  in the area of the exhaust and compression orifices/conduits. Not to overload the image the valves are not depicted.  
         [0016]      FIG. 4  shows a transverse section of the engine&#39;s stator taken in 4—4 plane in  FIG. 2  in the area of the intake and power orifices/conduits. Not to overload the image the valves are not depicted.  
         [0017]      FIG. 5  is an enlarged diagrammatic cross sectional view taken through the engine with arbitrary piston position during the rotation of the rotor. The gases conduits, their orifices and valves are diagrammatically shown side by side in one plane to better illustrate their relative operation, whereas if shown as they appear in the drawing of  FIG. 2 , no cross section would show all of them, and their simultaneous operation could not be seen. The guiding grove for the piston is illustrated with closely spaced hatching. All valves are shown in the closed positions.  
         [0018]      FIGS. 6-9  show similar cross sectional view to that of  FIG. 5 , but corresponding to the valves positions during intake ( FIG. 6 ), compression ( FIG. 7 ), power ( FIG. 8 ) and exhaust ( FIG. 9 ) cycles. Piston positions are shown arbitrary at each cycle during the revolution of the rotor. The arrows inside the engine show gas flows during each cycle.  
         [0019]      FIG. 10  shows similar cross sectional view to that of  FIG. 5 , but illustrating consecutive positions of the piston during rotational stages of the rotor corresponding to the contouring by the piston of the inner surface of the stator in the area of the combustion chamber. All valves are shown in the closed positions.  
         [0020]      FIG. 11  shows similar cross sectional view to that of  FIG. 5 , but illustrating the modification of the engine with two pistons and two combustion chambers. The pistons are at arbitrary positions, and all valves are shown in the closed positions. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [heading-0021]     Objects and Advantages  
         [0022]     The object of the invention is to create simple RICE with minimum parts and lack of radial constituent of force of expanding gasses applied to a piston providing high torque on engine rotor.  
         [0023]     This object is attained in that in RICE comprising the vane-type piston that is moving in radial direction within a radial groove made in a cylindrical rotor along its whole length (height). The rotor being positioned in a cylindrical body of a stator whose inner surface is arranged of two concentric surfaces, of which the one with smaller radius has the same radius as that of the rotor, and transitions between two concentric surfaces are arranged with ramp surfaces. This object is also attained in that the piston is provided by a means allowing it to tightly contour with its outer facet the inner surface of the stator ensuring gas sealing from its both sides. A cavity within the stator made in the area where the inner surface of the stator has the same radius as that of the rotor form a combustion chamber. A space between ramp surfaces of the stator and side planes of the piston form working chambers, which are connected to the combustion chamber, intake and exhaust systems via valve-controlled orifices.  
         [0024]     One of possible solutions for the mechanism allowing radial movement of the piston in a manner that its outer facet tightly contours the inner surface of the stator, preventing leak of gasses between working chambers formed on both sides of the piston, is creating a guiding grooves, concentric with the whole system, in a lids that form the bases of the cylindrical body of the engine that mimic the inner surface of the stator, and providing the piston with a lugs that move in the guiding groves.  
         [0025]     The engine can be made as one unit with up to four combustion chambers or as an assembly of several units each with single combustion chamber.  
         [0026]     In the simplest embodiment with one combustion chamber one complete revolution of the rotor performs one complete cycle of a four-stroke engine.  
         [heading-0027]     Preferred Embodyment— Figs. 1-5   
         [0028]     Major parts of the proposed invention are presented on  FIG. 1 ,  FIG. 2 ,  FIG. 3 ,  FIG. 4  and  FIG. 5 . A rotary internal combustion engine comprises a rotor  20  having a cylindrical body  22  sitting on a shaft  24 . The cylindrical body of the rotor has a radial grove  26  made along its whole height. The grove of the rotor houses a piston  30  having a rectangular body  32  whose height equals the depth of the groove  28 , length equals the height of the cylindrical body of the rotor and width equals the width of the grove. The piston can freely move in radial direction within the grove of the rotor. In current version of the engine design the piston is provided with a cylindrical lugs  34  on its sides facing the bases of the rotor as part of the mechanism that allows radial motion of the piston. The rotor  20  with the piston  30  is mounted within a prism-shape stator  10  of the same height as that of the rotor concentrically to its inner cylindrical surface  12  with the help of a two side cover lids  40  and  50  having openings  43  and  53  for the rotor&#39;s shaft  24  concentric to the rotor and to the inner surface of the stator. The surfaces of the lids  40  and  50  facing the stator&#39;s interior have an annular guiding grooves  42  and  52  into which the lugs  34  of the piston  30  fit to form one probable mechanism that allows radial motion of the piston during rotation of the rotor  20 . The shape of the guiding groove has to be made such that it would provide tight contouring of the inner surface  12  of the stator  10  by the piston&#39;s body  32  outer facet. Whole assembly of the rotor  20 , piston  30 , stator  10 , lids  40  and  50  is secured by bolts  54  and nuts  44 .  
         [0029]     The diameter of the inner cylindrical surface  12  of the stator  10  has to be such that to ensure secure positioning of the piston  30  within the grove  26  of the rotor  20  while the piston is pulled out in radial direction from the grove to be pressed with its outer adge against the inner surface of the stator. Within the short distance on the perimeter of the inner cylindrical surface  12  of the stator  10  its diameter is made equal to that of the cylindrical body  22  of the rotor  20 , and the inner surface with smaller diameter smoothly transits to the surface with bigger diameter with surface ramps. In the area where the diameter of the inner cylindrical surface  12  of the stator  10  equals that of the cylindrical body  22  of the rotor  20  a cavity, which forms a combustion chamber  14  is made within the body of the stator  10 . The combustion chamber  14  is connected to the working chamber  13  of the engine formed between the outer surface of the cylindrical body  22  of the rotor  20  and the inner cylindrical surface  12  of the stator  10  with bigger diameter via a compression orifice  64  and power orifice  16  made in the ramp areas of the inner surface  12  of the stator  10  and controlled by a compression valve  84  and a power valve  18 , respectively (see  FIG. 5 ). A spark-plug  62  faces the volume of the combustion chamber  14 .  
         [0030]     A fuel intake conduit/orifice  68 , controlled by an intake valve  88 , made within the body of the stator  10  in the immediate vicinity to the power orifice  16 , connects fuel injection system A to the working chamber  13  of the engine formed between the outer surface of the cylindrical body  22  of the rotor  20  and the inner cylindrical surface  12  the stator  10  with bigger diameter.  
         [0031]     An exhaust conduit/orifice  66 , controlled by an exhaust valve  86 , made within the body of the stator  10  in the immediate vicinity to the compression orifice  64 , connects the working chamber  13  of the engine formed between the outer surface of the cylindrical body  22  of the rotor  20  and the inner cylindrical surface  12  the stator  10  with bigger diameter to the exhaust system B.  
         [0032]     An ambience conduit/orifice  72 , controlled by an ambience valve  82 , made within the body of the stator  10  in the immediate vicinity to the power orifice  16 , connects atmospheric ambience C to the working chamber  13  of the engine formed between the outer surface of the cylindrical body  22  of the rotor  20  and the inner cylindrical surface  12  the stator  10  with bigger diameter to balance the pressure on one of the piston&#39;s  30  side.  
         [0033]     Two or more engines are easily arranged as an integral unit. In this case the lids (i.e., 40 or 50), which separate the engines will have to be made double-sided (i.e. with 42-like guiding grooves on both sides) and the shafts  24  of the rotors  20  facing each other have to be provided with fitting and connecting mechanism.  
         [heading-0034]     Operation of Invention— FIGS. 6-10   
         [0035]     The engine operates in the following manner (see  FIG. 6 ,  FIG. 7 ,  FIG. 8 ,  FIG. 9 ,  FIG. 10 ):  
         [0036]     The rotor  20  during engine operation rotates clockwise. The first, suction cycle ( FIG. 6 ) starts when the piston body  32  has just passed the intake orifice  68 . At this point the intake valve  88  opens whereas the exhaust valve  86  remains open from previous (fourth) cycle. The depression created on the side of the piston body  32  facing the intake orifice  68  during clockwise rotation of the rotor  20  helps to suck in the fuel mixture A into the working chamber  13  whereas the excessive positive pressure created on the side of the piston body  32  facing the exhaust orifice  66  is dissipated via the open exhaust gas conduit B. Immediately after the piston body  32  enters the region underneath the combustion chamber  14  (see  FIG. 10  for consecutive positions of the piston  30  during contouring the combustion chamber  14 ) both the intake valve  88  and the exhaust valve  86  close, and the fuel mixture remains locked in the working chamber  13 .  
         [0037]     The second, compression cycle ( FIG. 7 ) starts when the piston body  32  exits the region underneath the combustion chamber  14  (see  FIG. 10  for consecutive positions of the piston  30  during contouring the combustion chamber  14 ). At this time the compression valve  84  opens the compression orifice  64  into the combustion chamber  14 . The excessive positive pressure created on the side of the piston body  32  facing the compression orifice  64  helps to drive the fuel mixture from the working chamber  13  into the combustion chamber  14 . Immediately after the piston body  32  passes the ambience orifice  72  during clockwise rotation of the rotor  20  the ambience valve  82  opens as well helping to dissipate the depression created on the side of the piston body  32  facing the ambience orifice  72  by letting the atmospheric ambient air C into the working chamber  13 . Immediately after the piston body  32  during clockwise rotation of the rotor  20  passes the compression orifice  64  and enters the region underneath the combustion chamber  14  (see  FIG. 10  for consecutive positions of the piston  30  during contouring the combustion chamber  14 ) the compression valve  84  as well as the ambience valve  82  close. At the end of the second, compression cycle the compressed fuel mixture remains locked in the combustion chamber  14 , whereas the working chamber  13  remains filled with ambient air at atmospheric pressure.  
         [0038]     The third, power cycle ( FIG. 8 ) starts when the piston body  32  exits the region underneath the combustion chamber  14  (see  FIG. 10  for consecutive positions of the piston  30  during contouring the combustion chamber  14 ) and just passes the power orifice  16 . At this time the power valve  18  opens and synchronously the spark-plug  62  ignites the compressed fuel mixture in the combustion chamber  14 . Expanding combusted gases exit through the power orifice  16  from the combustion chamber  14  to the working chamber  13  and apply force to the side of the piston body  32  that faces power orifice  16  providing thereby the torque to the rotor  20  in the clockwise direction. At the beginning of the power cycle the exhaust valve  86  opens as well letting the atmospheric air B, working chamber  13  was filled in, through the exhaust orifice/conduit  66  out of the working chamber dissipating thereby the excessive positive pressure created on the side of the piston body  32  facing the exhaust orifice  66 . Immediately after the piston body  32  during clockwise rotation of the rotor  20  enters the region underneath the combustion chamber  14  (see  FIG. 10  for consecutive positions of the piston  30  during contouring the combustion chamber  14 ) the power valve  18  closes. At the end of the third, power cycle the combustion chamber  14 , as well as working chamber  13  are filled with burned fuel gases.  
         [0039]     The last, fourth exhaust cycle ( FIG. 9 ) starts when the piston body  32  exits the region underneath the combustion chamber  14  (see  FIG. 10  for consecutive positions of the piston  30  during contouring the combustion chamber  14 ) and just passes the ambience orifice  72 . At this time the ambience valve  82  opens whereas the exhaust valve  66  still remains open from the previous cycle. The excessive positive pressure created on the side of the piston body  32  facing the exhaust orifice  66  during clockwise rotation of the rotor  20  drives burned gasses B through the exhaust orifice/conduit  66  to the exhaust system whereas open ambience valve  82  lets atmospheric air C into the working chamber  13  through the ambience orifice/conduit  72  to compensate for the depression created on the side of the piston body  32  facing the ambience orifice  72 . Immediately after the piston body  32  during clockwise rotation of the rotor  20  enters the region underneath the combustion chamber  14  (see  FIG. 10  for consecutive positions of the piston  30  during contouring the combustion chamber  14 ) the ambience valve  82  closes. At the end of the fourth, exhaust cycle the working chamber  13  becomes filled with atmospheric air at normal pressure and the combustion chamber  14  remains filled with the remnant of burned fuel gases.  
         [0040]     Now the cycles are repeated by going to the first, intake cycle.  
         [heading-0041]     Alternative Embodiments— Fig. 11 .  
         [0042]     The proposed engine instead of one piston, one combustion and one working chamber can be made with up to four of each.  FIG. 11  shows an example with two pistons, two combustion and two working chambers. In the event of multiple pistons/chambers in each part of the engine specific engine cycle is performed.  
       CONCLUSION, RAMIFICATIONS, AND SCOPE OF INVENTION  
       [0043]     Thus the reader will see that the RICE of the invention has simple design with minimum parts ensuring low cost of production, and provides the most effective interaction of expanding gases with the piston the force of which is directed exclusively tangential to the rotor generating thereby high torque.  
         [0044]     While my above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of one preferred embodiment thereof. This especially relates to the design of the system providing tight contouring of the stator&#39;s inner surface  12  by the outer facet of the piston body  32 . For example, the shape of the guiding groove  42  and  52  for the piston  30  can be made less curved if it is combined with the variable length piston body  32  (i.e. piston body  32  consisting of two resiliently connected with each other parts). Moreover, because of lack of radial constituent of the force of expanding gases applied to the piston it can be constantly kept pressed against the inner surface  12  of the stator  10  by means of springs only placed in the grove  26  of the rotor underneath the piston body  32 . In this case the need in the guiding grooves  42  and  52  and in the piston lugs  34  may be circumvented at all. To permit adjusting of the shape of the pistons outer facet to the variable curvature of the inner surface  12  of the stator  10  the piston body  32  or part of it can be made not from the solid piece of metal, but be assembled from the independently moving plates. Such piston design will also help for better pressurizing compartments on both sides of the piston and prevent leak of gasses between them.  
         [0045]     Accordingly, the scope of the invention should be determined not by the embodiment(s) illustrated, but by the appended claims and their legal equivalents.