Abstract:
A rotary engine has a driving shaft and a driving rotor secured in rotation to the driving shaft. The driving rotor has one or several outwardly open rotor chambers distributed around its periphery and each having several inclined pressure application walls that act as a kind of driving blade to convert the explosion pressure into a rotary motion of the rotor. A stator surrounds the driving motor and contains at least one explosion chamber inwardly open toward the driving rotor and provided with an outlet past which the rotor chambers move with at least two pressure application walls at the same time. An electric ignition plug is arranged in each explosion chamber and at least one valve-controlled mixture inlet or a valve-controlled air inlet and a valve-controlled fuel inlet open into the explosion chamber.

Description:
This application is a 371 of PCT/EP96/02316 filed May 30, 1996. 
    
    
     BACKGROUND INFORMATION 
     1. Field of the Invention 
     The invention relates to a rotary internal combustion engines. 
     2. Description of the Related Art 
     One such rotary engine is known from German Published, Non-Examined Patent Disclosure DE-OS 2 357 985. In it, two diametrical explosion or combustion chambers are present, which open radially to the rotor. The rotor is embodied over its entire circumference with individual rotor chambers, whose walls subject to combustion pressure extend obliquely to the radial direction. Such an engine has the disadvantage among others that radial explosion surges occur, which lead to engine vibration and energy losses. Another problem is sealing off the rotor chambers from the surrounding stator, because the immediately adjacent rotor chambers are sealed off only in linear fashion. This impairs the efficiency. The known engine must be started with a typically electrical starter. 
     Engines of similar construction have combustion chambers that are valve-controlled in a complicated fashion on the outlet side. 
     OBJECT AND SUMMARY OF THE INVENTION 
     The object of the present invention is to embody an internal rotary combustion engine in such a way that with high efficiency it operates very smoothly and starts automatically without a typical electrical starter. 
     To attain this object, a rotary internal combustion engine of the type defined by the preamble to claim 1 is distinguished according to the invention by the characteristics recited in the body of that claim. 
     Because of the angular arrangement of each chamber outlet relative to the wall subject to combustion pressure moving past it, and because of its predominant radial orientation, optimal energy yields and vibration-free engine operation are obtained. The pressure-tight machined seat in the region between the rotor chambers adjacent one another but spaced apart relatively widely favors the pressure buildup in the combustion chambers and promotes efficiency. With the external or cooling air aspirated by the aspirating rotor, effective engine cooling is attainable. With the compressor rotor, a supply of compressed air is built up during engine operation in the pressure reservoir, and this supply is utilized for automatic engine starting. Hence a separate electrical starter is unnecessary. In engine operation, the pressure built up in the pressure reservoir is also utilized to supply the combustion chambers with compressed air and fuel that is that the same pressure. 
     The features recited in claims 2 and 3 allow a gentle connection of the engine as needed to an element that is to be driven. Especially favorable energy conditions are made possible by the refinement of claim 4. 
     With the provisions of claims 5 and 6, the ignition energy for the spark plugs can be generated in a very simple and rational way in the combustion chambers. 
     If in accordance with claim 7 during one complete explosion surge walls subject to combustion pressure constantly move past the chamber outlet, major efficiency in conjunction with smooth engine operation is attainable. The embodiment of claim 8 has proven especially advantageous in this respect. 
     A favorable structural design is obtained by the characteristics of claims 9-13. The exhaust gases can flow into the exhaust gas outlet or removal duct. Choking of the rotor chambers on the outlet side improves the energy conversion. The rotor drive blades that dip into the exhaust gas outlet or removal duct lead to a further improvement in efficiency. 
     The delivery of fuel and air at the proper time can be accomplished highly expediently with the characteristics of claims 14 and 15. 
     With the characteristics of claims 16 and 17, the freedom from vibration and the energy yield can be improved. 
     The features of claims 18-21 enable simple control of the individual operational sequences. The valve slide controls the corresponding connections for the compressed air and for the compressed air compressed by the compressor rotor and supplied to the pressure reservoir. The starting valve upon automatic engine starting controls the inflow of compressed air to the rotor blades of the exhaust gas rotor. As a result, the engine can be started up very simply. 
     A tank closure operating in three phases as defined by claims 22 and 23 assures an organization as needed of the flow connections in the pressure reservoir. As a result, the fuel tank normally communicating with the pressure reservoir can be temporarily disconnected fluidically from it and vented when the tank is being refilled. 
     Especially good supplies of compressed air can be stored up in accordance with claim 24 by accomplishing this both internally and externally to the engine. 
     In the alternative design of claims 25 and 26, the exhaust gas is carried out of the rotor chambers to the outside via openings in the stator that are offset along the circumference relative to the combustion chambers. 
     An embodiment that is especially preferred from the standpoint of assembly and disassembly is obtained by means of the disklike, clampable design in claim 27. 
     The further feature of claim 28 includes a preferred type of fuel delivery via a fuel control valve, as well as via a ring line supplied thereby and via individual fuel supply lines. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be described below in further detail in terms of exemplary embodiments shown in the drawing wherein 
     FIG. 1 is a central longitudinal sectional view through a rotary internal combustion engine of the present invention; 
     FIG. 2 shows the engine of FIG. 1 in a longitudinal section offset from that view; 
     FIG. 3 is a cross sectional view through the engine of FIG. 1 taken along the line III--III of FIG. 1; 
     FIG. 4 show in a cross sectional view corresponding to FIG. 3, an alternative engine having only outward-opening rotor chambers and having external exhaust gas outlet openings; 
     FIGS. 5A and 5B are views taken along the line V--V of FIG. 1 of a rotatable valve slide; 
     FIGS. 6A, 6B, 6C and 6D show cross-sectional views through the region of a valve, and a cam controller for the valve; 
     FIG. 7 is a cross sectional view taken along the line VII--VII of FIG. 1 to illustrate ignition means; 
     FIG. 8 is a cross sectional view taken along the line VIII--VIII of FIG. 2 to illustrate fuel delivery; and 
     FIG. 9 is a view taken along the line IX--IX of FIG. 2 to illustrate a valve cam controller. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In FIGS. 1 and 2, a plurality of disklike engine elements 81 are arranged concentrically one after the other and clamped by peripheral threaded bolts 90. Such an engine comprising modules can be assembled and disassembled very simply by slipping the individual modules onto a central drive shaft 12 in wedged fashion, fixed against relative rotation, and longitudinally clamping them. The bolts may each have a bolt shoulder that enables separate assembly and disassembly of the engine parts on the two sides of the bolt shoulder. 
     The drive shaft 12 is connected via a centrifugal coupling 29 in FIG. 1 to an output shaft, which in turn is coupled to an element to be driven. In a manner not shown, the centrifugal coupling can be followed immediately by an energy-storing rotary mass, such as a flywheel 100. 
     This flywheel can temporarily drive the element to be driven during operation even if the centrifugal coupling has become unsnapped. Preferably this is a detent coupling, which snaps gently into engagement as the engine runs up to speed, when a certain rpm difference is exceeded, and comes unsnapped gently when the engine runs to a stop or becomes overly slow relative to the rotary mass. 
     The key point of the engine is embodied by a drive rotor 1, with a stator 3 associated with it. As shown in FIGS. 3 and 4, in the present case four uniformly distributed explosion or combustion chambers 5 are provided in the stator 3, with their valveless chamber outlets 7 extending predominantly at a tangent to the rotor circumference. As shown in FIG. 2, one spark plug 37 and one valve 80 on a valve rod 47 protrude into each combustion chamber 5 to deliver compressed air and fuel that is at the same pressure. When the fuel-air mixture is made to explode, the explosion pressure can be discharged via the chamber outlet 7 predominantly at a tangent inward into a rotor chamber 10 (FIG. 3) or 75 (FIG. 4) of the drive rotor 1. 
     In the circumferential region of the drive rotor 1, in the present case, six uniformly distributed rotor chambers 10 (FIG. 3) and 75 (FIG. 4) are formed, each having a plurality of walls subject to combustion pressure 9 extending approximately radially; specifically, in FIG. 3 there are two walls subject to combustion pressure 9 and in FIG. 4 there are three (in terms of the direction of drive rotation). 
     Between the drive rotor 1 and its stator 3, a relatively narrow machined seat is provided, which allows problem-free and wear-free rotation of the rotor and at the same time assures extensive pressure sealing between these parts whenever the chamber outlet 7 is opposite the rotor circumference rather than a rotor chamber 10 or 75. The mixture in the combustion chambers is correspondingly ignited in synchronized fashion whenever a rotor chamber is just beginning to move past. Hence the explosion pressure can act from the very outset approximately at a right angle on the walls subject to combustion pressure 9 moving past in succession, which leads to rotation of the rotor. 
     The rotor chambers 10 of FIG. 3 communicate on their radial inner side--preferably via a certain choking--with a central, annular exhaust gas outlet or removal duct 39, which as shown in FIG. 1 extends to the outside at the engine outlet. In contrast to this, the rotor chambers 75 of FIG. 4 are closed on the inside. Here, the exhaust gas is carried out via external exhaust gas outlet openings 79 (which communicate with the central exhaust gas outlet or removal duct 39 as in FIG. 3) in the stator 3, as soon as the rotor chambers 75, after the explosion events, move past these outlet openings. After the explosion, the exhaust gas can flow out of the associated rotor chamber 10 or 75 as described above. 
     The drive rotor 1 is preceded by an aspirating rotor 15, rotating in slaved fashion with it, that has a stator 33. This aspirating rotor aspirates external or cooling air, which in turn is carried for cooling through the drive rotor 1 and via and/or through the stator 3 surrounding it and having the combustion chamber or combustion chambers 5. In the present case, the aspirating rotor 15 and its stator 33 are embodied as in FIG. 7 with electromagnetic ignition means 35, which are connected to the spark plugs 37. Upon rotation of the aspirating rotor 15, ignition pulses synchronized thereby are generated for the explosion events in the combustion chambers 5. 
     The drive rotor 1 is followed by a compressor rotor 17, 43, rotating in slaved fashion with it, with a stator 45. The rotor compresses the external or cooling air carried to it during engine operation from the aspirating rotor 15 via the drive rotor 1 and its stator 3. In engine operation, the compressed air present on the compression side 63 of the compressor rotor 17, 43 proceeds at least in part via a more or less wide-open valve slide 59 and via check valves 19 following the latter to reach a pressure reservoir 21. If the valve slide 59 is not fully open in partial-load operation, then some of the compressed air from the compression side 63 passes via the valve slide 59 to outward-opening outflow ducts 61 that discharge into the exhaust gas outlet or removal duct 39. When the valve slide 59 is closed, the compression side 63 communicates only with the outflow ducts 61. 
     The pressure reservoir 21 includes an external fuel tank 23 including valve 101 and tank closure cap 102, and a compressed air chamber that normally communicates fluidically with it, which in the present case comprises an external compressed air chamber 67 and communicating with it a compressed air chamber 68 that is internal to the engine. Thus during engine operation, a relatively large supply of compressed air, required for engine operation and for starting the engine, can be built up and stored in the pressure reservoir 21. 
     During engine operation, the compressed air passes out of the compressed air chamber 68 via the more or less wide-open valve slide 59 to a mixture forming prechamber 25, which can be seen in FIGS. 2 and 6. As soon as the valve 80 in FIG. 6 leading to the combustion chamber 5, as a result of a valve control cam 51 on the valve rod 47 moves out of a closing position 84 (valve stroke 3) to a first, smaller opening position 82 (valve stroke 1), initially only compressed air flows into the combustion chamber 5. As the valve opens wider, up to a second opening position 83 (valve stroke 2), finally the fuel at the same overpressure (from the fuel tank 23 via a ring line 56 and via fuel supply lines 58) likewise reaches the combustion chamber 5, via an additional or tappet valve 48 that then opens and is embodied on or connected to the valve rod 47 (and via the aforementioned valve 80). After that, the valve 80 is returned to the closing position 84 (valve stroke 3), and the mixture is ignited. The valve stroke sequence described is repeated accordingly. 
     The valve control cam 51, as shown in FIGS. 6 and 9, engages a correspondingly shaped cam track 49, which in the present case is embodied on the compressor rotor 17, 43 and rotates with it. As a result, the control cam 51 (during valve strokes 1, 2 and 3), via the valve rod 47, can control the described synchronized delivery of compressed air and fuel under pressure. 
     Finally, the compressor rotor 17, 43 is also followed by an exhaust gas rotor 27 that also rotates in slaved fashion via the drive shaft 12. When the engine is started, compressed air stored in the pressure reservoir 21 is carried via an intermittently opened starting valve 65 to the rotor blades of the exhaust gas rotor 27, so that the engine can be set into rotation solely by means of this compressed air. For engine starting, the valve slide 59 is also opened, so that the combustion chambers 5 under valve control can be filled with the mixture to be ignited, and once engine starting has occurred, compressed air compressed by the compressor rotor 17, 43 can pass via the check valves 19 to reach the pressure reservoir 21, so that the pressure reservoir remains constantly charged for operation and for any later engine starting. 
     For the sake of an improved energy yield, some rotor blades 41, which belong to the four rotors 1, 15, 17, 27, dip into the exhaust gas outlet or removal duct 39. 
     In FIG. 5, the valve slide 59 is rotatable between a completely closed position a and a completely opened position b. In the closed position (FIG. 5, left portion of the left drawing), the outer compressed air connections 60 (radially outer openings on the valve slide 59) from the pressure reservoir 21 to the mixture forming prechamber 25 are interrupted. The flow connections between the compression side 63 of the compressor rotor 17, 43 and the check valves 19 are interrupted as well. However, the compression side 63 communicates with the outflow duct 61 via the valve slide 59. In the open position (FIG. 5, right-hand portion of the left drawing, and FIG. 5, right drawing), the outer compressed air connections 60 from the pressure reservoir 21 to the mixture forming prechamber 25 are opened. The flow connections between the compression side 63 of the compressor rotor 17, 43 and the check valves 19 are also opened. However, the compression side 63 is disconnected from the outflow duct 61 via the valve slide 59. In the intermediate positions of the valve slide 59 located between the extreme positions, the aforementioned flow connections can be varied between fully open and fully closed; the connection with the outflow duct 61 is adjusted in contrary fashion to the other connections. Thus with the valve slide 59, in conjunction with a fuel control valve 55, the engine output and engine rpm can be varied. Each time the engine is in operation, the pressure reservoir 21 is recharged for a new engine start. 
     The aforementioned fuel control valve 55 is located in FIG. 1 in the flow connection between the fuel tank 23 and the ring line 56. For shutting off the engine it can be closed, and for engine operation, for supplying fuel to the ring line 56, it can be opened more or less widely. The function of the fuel control valve 55 can be manually controllable and/or may be coupled with that of the valve slide 59 by known linking means. The ring line 56 communicates with the region surrounding the corresponding additional or tappet valve 58 each via a respective fuel supply line 58, in which a fuel check valve, not shown, is located. When the fuel control valve 55 is open, the fuel in the ring line 56 is under pressure, and so the aforementioned fuel check valves in the fuel supply lines 58 are opened under pressure control, and replenishing fuel can flow in. If conversely the fuel control valve 55 is closed, then the pressure in the ring line 56 drops, and so the fuel check valves close and no further fuel can emerge from the ring line. For shutting off the engine, the fuel control valve 55 and the valve slide 59 for the compressed air are thus closed. Although the valves 80 and 48 continue to function under cam control as the engine slows down to a stop, still no further mixture can be formed, for the above reasons. 
     The starting valve 65 is temporarily opened only for engine starting, in which the valve slide 59 is also opened, so that the compressed air can start up the engine. After engine starting, the starting valve 65 is closed manually or automatically. 
     The fuel tank 43 that forms one part of the pressure reservoir 21 is provided with a separate tank closure, not shown, which assures that for tank filling the fuel tank is fluidically temporarily disconnected from the pressure reservoir and vented. To that end, a tank closure cap has four rotational positions. In the first rotational position (normal or operating position), the fuel tank 23 communicates with the pressure reservoir 21, and a tank vent is closed. In the second rotational position (first actuation phase), the communication with the pressure reservoir 21 is interrupted by a valve, and the tank vent is still closed. In the second rotational position (second actuation phase), the tank vent (valve) is opened, so that a pressure equilibrium with the ambient pressure can be established in the fuel tank 23. In the fourth rotational position (third actuation phase), which is attainable only in delayed fashion with a view to the requisite pressure equilibrium, the tank closure cap can be removed. After the tank is filled, the rotational positions of the tank closure cap are gone through in reverse order, until the normal or operating position is again attained. The individual parts of the tank closure may all be integrated into a correspondingly embodied, compact tank closure cap.