Abstract:
The rotary engine includes a circular stator, a circular rotor rotating about the stator; the rotor and the stator being separated by a circular cylinder and at least one element with two flanges. The rotor includes two compression pistons attached to the inner surface of the rotor. These two pistons are located at the two extremities of a first diameter of the rotor and kept substantially in contact with the outer surface of the stator. The stator includes a recess at each extremity of a diameter. Each recess forms a compression chamber with the compression piston positioned at the end of the recess in the direction of rotation of the rotor and one of the flanges of the element with two flanges, referred to as the cylinder head flange. The motive force is applied to the compression piston when the pressure of the gases inside the compression chamber is suddenly increased to a predefined value.

Description:
TECHNICAL FIELD 
     The present invention relates to gasoline or compressed air rotary engines based on the rotational motion of a rotor, and relates particularly to a rotary engine with a circular rotor. 
     STATE OF THE ART 
     Vehicle engines currently in use are internal combustion engines comprising reciprocating pistons in which the motive force is produced by the explosion of a mixture of air and fuel such as gasoline. Each piston, housed in a cylinder, is pushed away violently by the explosion and causes a crankshaft to rotate via a connecting rod. However, these engines have a major drawback in that the stroke of the piston in the cylinder is limited to about eight cm. The lever arm of the crankshaft is therefore limited to about four cm, and therefore all the motive force occurs on these four cm of the lever arm, significantly limiting the engine torque. 
     The use of rotary engines has thus been considered in place of reciprocating engines. The operation of rotary engines is slightly more complex than that of traditional piston engine. Unlike an internal combustion engine, which operates thanks to pistons, rotary engines use a rotor. Unlike internal combustion engines, rotary engines comprise neither connecting rods nor crankshaft. 
     There are advantages to using rotary engines rather than reciprocating engines. First, because this engine has no reciprocating parts, it is very well balanced; this ensures its vibration-free operation, thus limiting the noise level regardless of engine speed. Secondly, this engine causes less vibration, since all the parts follow the same path as they all rotate in the same direction. In addition, since there are fewer moving parts in the engine, the rotary engine is more reliable. 
     A known engine of this type comprises a rotor that performs an oval-shaped orbital movement inside a housing. The main element of this engine, the rotor, is a triangular object positioned right in the center of the engine. This rotor performs an almost oval orbit within the housing, which is called a “stator”. With each rotation, the extremities of the rotor are always in contact with the stator. These contacts therefore form the compression chambers, namely three in all. There is a crank in the center of this rotor, which consists of two toothed gears: one large and one small. The larger gear thus mates with the smaller one to define the path of the rotor in the housing. 
     But this type of rotary engine presents a number of drawbacks. For example, the number of revolutions per minute must be much higher than in a conventional engine. For example, to obtain optimum power, about 8500 RPM must be reached. This has the disadvantage of not producing very high torque at low engine speed. Under 5000 RPM, nothing happens, no torque is discernible. The disadvantage of this high speed is that the oil used as a lubricant will burn. It is not possible to remove the oil without encountering sealing problems. Finally, another drawback is fuel consumption which is at least 20% higher than reciprocating engines of equal power. 
     It is therefore better to use a rotary engine whose rotor is circular and rotates around the stator, as in the case of the engine described in document DE 3146782. But this engine does not comprise a compression chamber with an adequate seal. 
     BRIEF DESCRIPTION OF THE INVENTION 
     Therefore the aim of the invention is to provide a rotary engine with circular rotor rotating around a stator which has a perfect seal and does not require the use of lubricants. 
     Another aim of the invention is to provide a rotary engine with circular rotor rotating around a stator which allows engine torque to be relative to the diameter of the rotor and much higher than that of existing engines. 
     The subject of the invention is therefore a rotary engine comprising a circular stator, a circular rotor rotating about the stator; the rotor and the stator are separated by a circular cylinder and at least one element with two flanges. The rotor comprises two compression pistons attached to the inner surface of the rotor; these two pistons are located at the two extremities of a first diameter of the rotor and kept substantially in contact with the outer surface of the stator. The stator comprises a recess at each extremity of a diameter; each recess forms a compression chamber with the compression piston positioned at the end of the recess in the direction of rotation of the rotor and one of the flanges of the element with two flanges, referred to as the cylinder head flange; the motive force is applied to the compression piston when the pressure of the gases inside the compression chamber is suddenly increased to a predefined value. 
     According to a first embodiment, the engine according to the invention is used as an internal combustion engine in which each of the recesses comprises a gasoline inlet line and a spark plug; the gasoline is injected into the compression chamber by the fuel inlet line when the compression piston is in front of the recess and the transit and cylinder head flanges of the flanged element are closed, and the spark plug is activated when the compression piston is at the end of the compression chamber, with the transit flange open, such that the explosion of the fuel and gasoline mixture in the compression chamber produces the motive force on the compression piston. 
     In a second embodiment, the motor according to the invention is used as a compressed air motor. In this case, each of the recesses comprises a compressed air inlet line, compressed air is injected into the compression chamber associated with each recess when the compression piston arrives at the end of the compression chamber, with the transit flange open, so as to produce the same motive force as the explosion of the air-gasoline mixture of the same internal combustion engine. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The aims, subjects and characteristics of the invention will become clearer on reading the following description with reference to the drawings, in which: 
         FIGS. 1A ,  1 B,  1 C and  1 D are cross-section views of the engine showing each of the engine&#39;s components for four successive positions of the engine after it has turned 90° anticlockwise from each position in relation to the previous position; 
         FIG. 2  is a perspective view of the element with two flanges; 
         FIGS. 3A ,  3 B and  3 C are cross-section views showing the progression of the compression piston in the compression chamber from its entry into the chamber until the moment of explosion of the air-gasoline mixture; and 
         FIG. 4  is a cross-section view of the engine, perpendicular to the cross-section of  FIG. 1A ; it shows the rotor surrounding the stator and the two flanged elements, as well as these elements being driven by a belt from the rotor shaft. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The rotary engine according to a preferred embodiment of the invention, in which the engine is an internal combustion engine shown in  FIGS. 1A ,  1 B,  1 C and  1 D, comprises a stator  10  around which a rotor  12  turns. The rotor  12  is driven in anticlockwise rotation around a shaft  13 . The stator and rotor are separated by a space that constitutes the cylinder. The engine comprises four pistons fixed to the inner surface of the rotor  12 : two compression pistons  16  and  18  located at the two extremities of a rotor diameter and two intake/exhaust pistons  20  and  22  located at the two extremities of a diameter perpendicular to the previous one and therefore at a 90° angle to the two compression pistons. 
     At the same time that the rotor is driven in rotation about its shaft, two identical flanged elements  24  and  26  are also driven in rotation about their respective shafts  28  and  30 . Each flanged element comprises two flanges. Thus, the flanged element  24  shown in  FIG. 2  comprises a transit flange  32  and a cylinder head flange  34  connected by a rotational drive mechanism. The transit flange  32  allows the passage of the gases in cylinder  14  to the rear of the piston. 
     The two flanged elements  24  and  26 , seen in cross-section in  FIGS. 1A to 1D , are driven in rotation by the rotation of the rotor. The shaft  13  of the rotor  12  in rotary motion drives the shaft  36  associated with the flanged element  24  and the shaft  38  associated with the flanged element  26  by means of a belt  40 . Each of the shafts  36  and  38  drives respectively each of the shafts  28  and  30  of the associated flanged elements thanks to a bevel gear device, not shown in  FIG. 2 , which consists of two gears at a 45° angle to their axis, thus transforming a rotary motion around the shaft  36  or  38  into a rotary motion around the perpendicular shaft  28  or  30  respectively. 
     The stator  10  comprises two recesses  42  and  44  located at the two extremities of a diameter. Each of these two recesses comprises a gasoline inlet line, the line  46  for recess  42  and the line  48  for recess  44 , as well as a spark plug  50  for recess  42  and a spark plug  52  for recess  44 . 
     When the engine is in the position shown in  FIG. 1A , the two flanges of the flanged element  24  form a closed compression chamber  54  in which the compression piston  16  is located. The gasoline inlet through the line  46  is activated and the air-gasoline mixture is formed in the chamber thus formed. 
     The phase leading to the explosion is explained with reference to  FIGS. 3A ,  3 B and  3 C. In  FIG. 3A , the compression piston  16  reaches the beginning of the chamber  54 . Thanks to the opening of the cylinder head flange  34  while the transit flange is closed, the air in the chamber  54  begins to be compressed. Then, when the piston  16  reaches the middle of the chamber  54 , i.e. opposite the recess  42 , the two flanges  32  and  34  are closed and the gasoline is injected into the chamber through the inlet line  46  as shown in  FIG. 3B . Finally, when the piston  16  reaches the end of the chamber, the transit flange  32  is in its open portion and the spark plug  50  is activated so as to cause the explosion in the chamber  54  as shown in  FIG. 3C . This explosion allows a motive force to be exerted on the piston  16  and thus to drive the rotor in rotation. 
     When the engine is in the position shown in  FIG. 1B , the compression piston  16  has performed a 45° rotation thanks to the expansion of the air-gasoline volume  56  that has exploded and is blocked by the closing of the cylinder head flange  34  of the flanged element  24 . Air enters the cylinder  14  thanks to a turbocharger (not shown). 
     Note that the exhaust of the gases burned in the preceding explosion takes place at the front of the intake/exhaust piston  22  through an exhaust port  58 . When the engine reaches the position shown in  FIG. 1B , the volume of exhaust gas in the cylinder is reduced because the piston  22  moves forward so that this part of the cylinder is blocked by the cylinder head flange  34 . 
     When the engine is in the position shown in  FIG. 1C , the compression piston  16  has performed a 180° rotation since the explosion. The intake/exhaust piston  22  is then opposite the recess  42  of the stator. The volume  56  of burnt gases is at its maximum expansion and the burnt gases begin to escape through the exhaust port  58 . The air that entered the cylinder then occupies the portion  60  that is its maximum volume between the compression piston  18  and the closed cylinder head flange  34 . 
     When the engine is in the position shown in  FIG. 1D , the compression piston  16  has already completed ¾ of a turn. The air in the portion  56  continues to escape through the exhaust port  58 . The volume of the portion  60  of the cylinder begins to be compressed because it is trapped between the transit flange  32  (cylinder head flange open) and the intake/exhaust piston  18 . 
     Then, when the piston  18  reaches the top of the recess  42 , it has taken the place of piston  16  as shown in  FIG. 1A . Therefore, the phases described with reference to  FIGS. 1A ,  1 B,  1 C and  1 D are reproduced in the same way, the pistons  16  being replaced by the pistons  18  and  20 , respectively. 
     Note that the phases just described with the pistons  16  and  22  are performed in the same way and at the same time with the pistons  18  and  20 . This means that the air and gasoline intake in the two diametrically opposed chambers takes place at the same time and that the spark plugs are activated at the same time in the two chambers. It is therefore unnecessary to describe them. 
     Thus it can be seen that at each half-turn of the rotor  12 , two explosions take place at the same time due to the compression pistons  16  and  18 . Therefore, there are four explosions at every revolution of the rotor, which is equivalent to two times a complete four-stroke cycle, compared to the reciprocating internal combustion engine that performs a four-stroke cycle in two revolutions of the engine. 
     In  FIG. 4 , which shows the engine along a cross-section A-A of  FIG. 1A , the transit flange of the flanged element  24  and the cylinder head flange of the flanged element  26  can be seen. Note that the two flanged elements  24  and  26  are offset by 180°, the transit flange of one of them is in alignment with the other&#39;s cylinder head flange and vice versa. 
     As shown in  FIG. 4 , the rotor  12  that comprises the two compression pistons  16  and  18  rotates around the stator  10 . The rotor rotates about the shaft  13  and the two flanged elements  24  and  26  rotate about their respective shafts  28  and  30 . These last are driven in rotation through the rotary motion of the rotor  12  about its shaft  13  which drives two primary shafts  36  and  38  in rotation by means of the belt  40 . The shafts  36  and  38  communicate the rotation respectively to the shafts  28  and  30  by means of bevel gear devices  60  and  62 . 
     Note that the diameter of the shafts  36  and  38  is equal to half the diameter of the shaft  13 . Thus, since the shafts  36  and  38  are driven by the belt  40 , their speed of rotation is twice that of the rotor  12 . It would be possible to make the flanged elements rotate at the same speed as the rotor. However this would require having four openings in each flange instead of two as is the case in the embodiment described hereabove. There could even be a single flanged element rotating at the same speed as the rotor. However the diameter of the flanged element would have to be at least double, which would increase the bulk. 
     The torque of the engine just described is a function of the rotor&#39;s diameter. Thus, the diameter of the rotor can be 40 cm, which allows torque five times greater than the torque of a reciprocating engine with a piston stroke of eight cm to be achieved. 
     As for sealing, the rotary engine just described comprises a spring (not shown) located on the back of each piston that keeps the piston in contact with the surface of the stator. As the speed increases after the engine has been started, the springs are compressed due to the centrifugal force and the pistons move slightly away from the surface of the stator. When the optimum speed is reached, this speed is such that there is a seal caused by the speed with no need for contact. When the engine stops, the pistons retract to come in contact with the surface of the stator and realize the seal at startup. Since there is no friction on the rotor as it turns, it is not necessary to use lubricant. 
     As regards cooling, it is performed by air from the rotating rotor. A ventilation device to the rear of the engine (not shown) forces air to move inside the engine so as to cool all the rotating parts. 
     Although the preferred embodiment is a rotary internal combustion engine, it is possible to operate the engine with compressed air. To achieve this, a compressed air inlet line is provided for each recess of the stator, the line  64  for the recess  42  and the line  66  for the recess  44 . A simple switch is sufficient to remove the fuel injection by the gasoline inlet lines  46  and  48  and to open the compressed air inlet lines  64  and  66 . The compressed air pressure is about 30 bar which corresponds to the gas pressure in the chamber after explosion. As shown in  FIG. 1A , the compressed air is injected into the compression chamber when the compression piston arrives at the end of the compression chamber, with the transit flange open and produces the same motive force as the explosion of the air-gasoline mixture of the same internal combustion engine. 
     Note that the embodiment using compressed air has a major advantage over current engines using an explosive fuel/air mixture in that there is no release of carbon dioxide and therefore zero pollution. This is a considerable advantage in the current fight against carbon emissions. 
     Note that it is possible to build a system combining several engines according to the invention. For example, a system using a combination of two engines can be envisaged. Such a system would comprise a single rotor rotating about two stators. In this case, four compression pistons would produce the motive force for each turn of the common rotor, i.e. eight explosions for an internal combustion engine. 
     In summary, all the following combinations can be considered in the case of an internal combustion engine: 
     two explosions per revolution compared to a four-cylinder reciprocating engine, 
     four explosions per revolution compared to an eight-cylinder reciprocating engine, 
     eight explosions per revolution compared to a sixteen-cylinder reciprocating engine, 
     sixteen explosions per revolution compared to a thirty-two-cylinder reciprocating engine.