EP3379027A1 - Combustion engine and method for operating same - Google Patents

Abstract

An internal combustion engine comprises an engine unit (1) having a first ignition chamber (40) comprising a fuel inlet for fuel and an ignition device (42) for igniting the fuel; a first piston housing (10) which forms an interior space (11) in which at least two rotary pistons (20, 30) are arranged; with a closable inlet (13) from the first firing chamber (40) to the interior (11), the rotors (20, 30) being driven by the exhaust gas produced by combustion of fuel in the first firing chamber (40). Each rotary piston (20, 30) has on its outer circumference at least two sealing strips (25, 26, 35, 36) and at least two recesses (27, 28, 37, 38), wherein the sealing strips of each one of the rotary pistons (20, 30) in the recesses of the other rotary piston (20, 30) sealingly engage. In addition, the sealing strips in the radial direction of the respective rotary piston (20, 30) for sealingly contacting a housing inner wall (12) are dimensioned. In addition, a method for operating such an internal combustion engine will be described.

Description

The present invention relates in a first aspect to an internal combustion engine.

In a second aspect, the invention relates to a method for operating an internal combustion engine.

In internal combustion engines, a fuel is burned to generate rotational energy. Depending on the application, the rotational energy can be further converted into other forms of energy. Such internal combustion engines may in particular be internal combustion engines for vehicles, for example gasoline or diesel engines. As fuel but can also be used hydrogen gas or any other combustible fluid in principle. Internal combustion engines of the type described here also include stationary versions in which the internal combustion engine, for example, together with a generator generates electrical power or is part of a power plant.

Internal combustion engines that are the subject of this disclosure include rotary engines. These offer certain advantages over reciprocating engines, for example, often simpler construction, which can result in a rugged design, a lower weight and cost savings. An example of a known rotary engine is the Wankel engine. A disadvantage of known rotary engines is the problematic sealing of the rotary piston. In addition, the highest possible efficiency of the internal combustion engine is generally desirable.

It can be regarded as an object of the invention to provide a combustion engine which is as efficient and as robust as possible, and also a method for operating a combustion engine which is as efficient and robust as possible.

Inventive solution

This object is achieved by the internal combustion engine having the features of claim 1 and by the method having the features of claim 15.

Advantageous variants of the internal combustion engine according to the invention and of the method according to the invention are the subject matter of the dependent claims and are also explained in the following description.

An internal combustion engine according to the invention comprises a first motor unit. This in turn comprises a first ignition chamber, which can also be referred to as a combustion chamber. The ignition chamber includes a fuel inlet for fuel to be combusted and an igniter for igniting fuel in the first ignition chamber. The first motor unit further includes a first piston housing defining an interior space in which at least two rotary pistons are disposed and a closable inlet from the ignition chamber to the interior space for introducing exhaust gas produced by combustion of fuel in the first ignition chamber. The interior of the first piston housing also has an outlet for exhaust gas. The at least two rotary pistons are driven by the exhaust gas, which flows from the ignition chamber through the interior to the outlet. Each rotary piston comprises at least two sealing strips and at least two recesses on its outer circumference. The shapes of the recesses and the sealing strips are selected for engaging the sealing strips of each one of the rotary pistons in the recesses of the other rotary piston of the same motor unit. The sealing strips are dimensioned in the radial direction of the respective rotary piston for sealingly contacting a housing inner wall.

• Einlassen von zu verbrennendem Kraftstoff in die erste Zündkammer,
• Entzünden von Kraftstoff in der ersten Zündkammer mittels einer Zündvorrichtung,
• Öffnen und Schließen eines schließbaren Einlasses von der ersten Zündkammer zum Innenraum, um Abgas einzuleiten, welches durch Verbrennung von Kraftstoff in der ersten Zündkammer entsteht, wobei die mindestens zwei Drehkolben vom Abgas angetrieben werden,
• Ausleiten des Abgases aus dem Innenraum des ersten Kolbengehäuses durch einen Auslass am Innenraum,
• wobei jeder Drehkolben an seinem Außenumfang mindestens zwei Dichtleisten und mindestens zwei Vertiefungen aufweist, wobei die Formen der Vertiefungen und der Dichtleisten gewählt sind zum Eingreifen der Dichtleisten von jeweils einem der Drehkolben in die Vertiefungen des jeweils anderen Drehkolbens,
• wobei die Dichtleisten in Radialrichtung des jeweiligen Drehkolbens zum dichtenden Kontaktieren einer Gehäuseinnenwand bemessen sind.

In a method according to the invention for operating an internal combustion engine, the internal combustion engine comprises a first engine unit, which in turn comprises a first ignition chamber and a first piston housing. The piston housing forms an interior in which at least two rotary pistons are arranged. The method comprises:

• Introducing fuel to be burned into the first ignition chamber,
• Igniting fuel in the first ignition chamber by means of an ignition device,
• Opening and closing a closable inlet from the first firing chamber to the interior to introduce exhaust gas resulting from combustion of fuel in the first firing chamber, the at least two rotors being driven by the exhaust gas,
• Discharging the exhaust gas from the interior of the first piston housing through an outlet at the interior,
• wherein each rotary piston has at least two sealing strips and at least two recesses on its outer circumference, the shapes of the recesses and the sealing strips being selected for engagement of the sealing strips of one of the rotary pistons in the recesses of the respective other rotary piston,
• wherein the sealing strips are dimensioned in the radial direction of the respective rotary piston for sealingly contacting a housing inner wall.

Further variants

In this case, the term "exhaust gas" should generally be understood as meaning the mixture which is produced by the combustion of fuel or a fuel-air mixture in the ignition chamber. The combustion of the fuel increases the pressure in the ignition chamber and, because of the connection to the interior, also to the rotary piston. The exhaust gas generated during combustion therefore presses against the rotary pistons and flows along them, whereby the rotary pistons are set in rotation. This rotational movement can continue to be used. In the example of a vehicle, the rotational energy is at least partially transmitted to drive wheels of the vehicle.

The sealing strips are dimensioned in the radial direction for sealingly contacting a housing inner wall. The radial direction refers to the radius of the associated rotary piston, whereby the radial direction is transverse or perpendicular to the direction of rotation of the respective rotary piston. The exhaust gas flowing along the rotary piston presses against some of the sealing strips, whereby these sealing strips are pressed against the housing inner wall. In this context, the housing inner wall is to be understood as a lateral surface with respect to the axes of rotation of the rotary pistons of the interior, not as end faces of the interior. In particular, depending on the rotational position at least one (or exactly one) of the sealing strips of each Rotary piston be exposed to the incoming exhaust gas and thus pressed by this against the housing inner wall.

Preferably, the sealing strips comprise a deformable or elastic material, so that they are deformed by the exhaust gas pressure and sealing against the housing inner wall can be pressed. The material of the sealing strips is easier to deform or more elastic than a material surrounding the sealing strips of the rotary piston, in particular as the material from which the grooves described in more detail below for receiving the sealing strips are formed.

The fuel to be combusted in the ignition chamber can basically be any flammable substance. For example, the fuel may be or include gasoline or diesel. It may be preferred that the fuel used is ethanol or an ethanol-containing fuel or alternatively hydrogen gas or a mixture with hydrogen gas. An ignition device for igniting the fuel may, for example, be a laser. An ignition device may also be understood to mean spark plugs or other devices for generating sparks or flames.

In order for a pressure arising from the combustion of the fuel to act efficiently on the rotary pistons, it may be preferable for the ignition chamber to adjoin the interior space in which the rotary pistons are arranged. For example, the ignition chamber may be flanged to the piston housing of the interior. Alternatively, the ignition chamber and the interior can also be connected by a pipe or another connection line.

A pressure from the ignition chamber can drive the rotary pistons relatively uniformly. Thus, the internal combustion engine differs significantly from, for example, 4-stroke internal combustion engines, which require a more complicated control due to the successive clocks and generate larger peak loads.

The closable inlet from the first ignition chamber to the interior space permits exhaust gas produced by the combustion to be passed from the ignition chamber into the interior space only at certain time intervals. In addition, by the closable inlet, a pressure drop can be generated, whereby loads on the deformable sealing strips are reduced.

The outlet from the interior can be formed as a closable outlet, which in principle can be constructed the same as the closable inlet. The following explanations on the closable inlet should therefore also apply to a closable outlet.

At each closable inlet there may be an inlet closing body which is movable for releasing and closing the inlet. The inlet closing body may be coupled to the rotary pistons such that a frequency and phase (as rotation angle) of the rotary pistons dictate or at least influence at which times the inlet closing body opens and closes. The coupling can be done via other components, for example via the drive shaft.

The inlet closing body may also be formed by the sealing strips. Due to the rotation of the sealing strips, they can drive over the inlet and cover it temporarily sealingly. Likewise, the sealing strips can serve as AuslassSchließkörper and temporarily cover one or more outlets from the interior sealing.

The closable inlet (and / or the closable outlet) may be formed in an end face of the interior. A contact surface of the sealing strips to the front side may be larger than a contact surface of the sealing strips to a lateral surface of the interior. Towards the lateral surface, a small contact surface is desirable in order to minimize friction losses. On the other hand, the size of the contact surfaces to the front determines how long the inlet (or outlet) will be covered.

A size of the contact surfaces of the sealing strips to the end face can be defined by the fact that the sealing strip has a notch toward the front side. In the area of the notch, the sealing strip does not contact the front side of the interior. Thus, by the notch, the closable inlet is released and a closing duration of the inlet is shortened. Alternatively or additionally, the sealing strips may have a widening towards the end face, by means of which the contact surface to the end face increases is. The broadening increases the closing time of the inlet (or outlet).

Alternatively or additionally, each inlet-closing body may also each comprise a rotatably mounted roller having a passage, so that depending on the rotational position of the roller, the associated inlet is opened or closed. The roll may in particular be formed as a slit roll or a cylindrical roll, the passage of which is a slit. A cross-sectional area of the slot toward the interior may be a different size than a cross-sectional area of the slot toward the firing chamber. In particular, this makes it possible to set flow characteristics of the introduction of exhaust gas into the interior. If the cross-sectional area decreases from the ignition chamber to the interior space, the velocity of the exhaust gas flowing through it increases and an inflow takes place in a relatively small conical area, whereby an efficient transfer of force to the sealing strips for rotating the rotary piston can be possible. However, it can also be provided an increasing cross-sectional area of the ignition chamber to the interior, which may be advantageous in terms of a more uniform distribution of the exhaust gas in the interior and, concomitantly, lower loads on the rotary piston and its sealing strips.

The rotational speed and rotational position of the slot roller can be clocked to ignite the fuel in the ignition chamber. Thus, it can be provided that the slot roller (or more generally the separating means) always release a connection to the interior with the rotary pistons when just the ignition takes place, or when a pressure after ignition is maximum, or at a predetermined time before or after one these processes.

There may also be a valve, in particular a solenoid valve, as an inlet closing body or outlet closing body. The valve may in particular be designed to effect a substantially constant metering of exhaust gas to the rotary pistons.

The rotation of the rotary pistons generates a suction effect, by means of which a residual gas, which remains in the ignition chamber after the combustion of the fuel, is sucked out of the ignition chamber. This then allows for the next ignition process a larger amount of fuel-air mixture are passed into the ignition chamber.

The sealing strips may extend in a longitudinal direction, which is substantially parallel to the axes of rotation of the two rotary pistons. In particular, an angle between the longitudinal direction and the axes of rotation may be less than 20 °, preferably less than 10 °.

The axes of rotation of the rotary pistons of a motor unit can likewise be parallel to one another or at least at an angle which is at most 40 ° or preferably at most 20 °. In addition, the rotary pistons of a motor unit can be formed identically. If asymmetrical sealing strips are used, as described later, then the rotary pistons can be identical except for a mirrored arrangement or shaping of the sealing strips.

Under a rotary piston, an object can be understood, which is rotatably mounted and rotates with rotation, a shaft. The rotation of this shaft can then be used, for example, to set other objects in rotation or in particular to generate electrical energy via a generator.

To attach the sealing strips to the rotary piston, the sealing strips can be received in grooves, that is to say grooves or other recesses, which are formed on the respective outer circumference of the rotary pistons. In particular, the grooves can be formed in later described in more detail sprockets of the rotary piston. In the grooves, the sealing strips can be attached in principle any way. The sealing strips can thus be exchangeable, so that when worn due to the sealing contact a slight change of the sealing strips is possible without further components of the internal combustion engine would have to be replaced.

In a preferred embodiment, the sealing strips are formed as sliding blocks for retaining engagement in the grooves in the rotary piston. By this is meant that the sealing strips have at their respective inner end, which is accommodated in the associated rotary piston, a thickening or a collar. The grooves in which the sealing strips are received, are shaped so that said thickening or the collar engages holding.

In particular, the grooves may be formed as T-grooves and each of the sliding blocks may include a laterally projecting collar for engaging one of the T-slots. In principle, alternatively or additionally, screw fasteners or adhesive connections can be provided for fastening the sealing strips in the grooves.

The sealing strips and the associated grooves can be shaped so that the sealing strips are held in the radial direction of the associated rotary piston, so are immovable. On the other hand, moving perpendicularly thereto, in particular in the direction of the axis of rotation of the rotary piston, can be possible (and thus insertion and removal) of the sealing strips. Thus, worn or abraded sealing strips can be easily replaced. It can also be provided that the sealing strips are used under bias in the direction of the axis of rotation, for example by a spring is used. This has the consequence that the sealing strips press under pretension against the end faces of the interior. If the inlet and the outlet are located on these end faces, then the sealing strips can seal them particularly reliably because of the prestressing.

In the longitudinal direction of the sealing strips (or in the direction of the axes of rotation of the rotary pistons), the sealing strips are preferably dimensioned such that they also effect a seal in this direction to the bottom and the ceiling of the housing interior.

The sealing effect of the sealing strips in the radial direction to the housing inner wall depends on the deformation of the sealing strips. It is advantageous if the exhaust gas pressure causes a deformation of the sealing strips to the housing inner wall, and not about a deformation away from the housing inner wall. Each of the sealing strips has a side which, in the case of a rotational angle position of the associated rotary piston, in which the sealing strip contacts the housing inner wall, faces the exhaust gas flowing in. This page will hereinafter be referred to as the exhaust gas contact side. In order to produce a deformation for the sealing contacting of the housing inner wall, the exhaust gas contact side preferably has no convex shape or at least on its inner wall facing the end of the end no convex shape. Rather, the exhaust gas contact side may rather have a concave shape or at least at its end facing the housing inner wall a concave Have shape. Alternatively, a substantially planar course of the exhaust gas contact side can also provide sufficient deformation depending on the circumstances.

Each of the sealing strips also has a rear side, which is opposite to the exhaust gas contact side. This rear side does not face incoming exhaust gas when there is a rotational angle position of the associated rotary piston in which the sealing strip contacts the housing inner wall or is adjacent thereto. The shape of the back also affects the deformation and thus the sealing effect. The rear side is preferably not concave or at least not concave on one end facing the inside wall of the housing. Preferably, the rear side is convexly shaped or at least convexly formed on an end facing the inner wall of the housing. A sufficient sealing effect can in turn be possible even with a linear or planar shape of the back.

The sealing strips may have an edge, at which a sealing contact with the housing inner wall is effected. An edge may result from a non-circular cross-section, especially if the exhaust contact side is concave and the back is convex.

Preferably, each rotary piston has (exactly or at least) three sealing strips, which are arranged at equal angular intervals on the outer circumference of the rotary piston. In particular, the angular distances can be rotational angles of 120 ° about the axis of rotation of the associated rotary piston. In addition, each rotary piston may comprise three recesses, which are located on the outer circumference at angular positions, which are also offset by 120 ° to each other and preferably each offset by 60 ° to the angular positions of the three sealing strips. This ensures that inflowing exhaust gas always presses against one of the sealing strips on each rotary piston and thereby causes a rotation of the rotary piston. In addition, it is achieved by this arrangement that regardless of a current rotational position of the rotary piston always a seal of both rotary pistons is provided to the housing inner wall.

The housing inner wall has in each case a circular section shape at the two regions in which the contact with the sealing strips of the two rotary pistons takes place. Each of these two circular sections may comprise an angular range of preferably at least 90 °, preferably more than 180 °. The circle center of each the circular sections preferably coincide with the axis of rotation of one of the rotary pistons. A radius of the circular sections is preferably equal to or slightly smaller than a radius of the rotary pistons (measured to the outer end of the sealing strips), which is conducive to the sealing contact.

Each of the rotary pistons may have a ring gear on its outer periphery. The rotary pistons can then be arranged so that their sprockets interlock. This largely prevents exhaust gas from flowing between the two rotary pistons. Rather, the exhaust gas is transported at the edge between the rotary piston and the housing inner wall. The sprockets may be interrupted by the depressions and sealing strips and extend, moreover, over the entire circumference of the two rotary pistons. Under a sprocket can be understood that an outer peripheral surface of the associated rotary piston has radially projecting teeth. Preferably, each tooth extends over the entire height of the rotary pistons along their axes of rotation.

In addition to a sealing effect is ensured by the intermeshing sprockets that both rotary pistons rotate at the same speed. This ensures that the sealing strips of one of the rotary pistons always hit the recesses of the other rotary piston.

In particular, due to temperature fluctuations, the relative position of the two rotary pistons to each other may change slightly. By interlocking the sprockets but also in such position fluctuations a sealing effect can still be achieved. By contrast, the sprockets would be unsuitable to provide a seal to the housing inner wall. Because here position fluctuations would lead to leakage due to lack of interlocking teeth. To avoid this, a seal to the housing inner wall is not effected by the sprockets, but by the sealing strips.

Depending on the rotational position of the two rotary pistons a largely sealing contact between them is provided either by the intermeshing sprockets, or by one of the sealing strips of one of the rotary pistons, which projects into one of the recesses on the other rotary piston.

The sealing strips can protrude in the radial direction of their respective rotary piston further outward than the respective sprocket. As a result, the ring gear is always spaced from the housing inner wall. In between, a separated region is formed, via which exhaust gas passes in the direction of the outlet opening. The separated area is limited in the circumferential direction of the rotary piston by the sealing strips. In the radial direction, the separated region through which exhaust gas is passed extends from the sprocket to the housing wall or the circular segment section of the housing wall.

For the size of the separated areas, the number of sealing strips is important. The more sealing strips are provided, the smaller each of the separated areas. A separated area is relevant to the intake volume as well as the expansion volume of a motor unit, whereby the expansion volume can result through several motor units. A size ratio of intake volume and the expansion volume relative to the ignition chamber is in turn important for a compression ratio and a relaxation ratio and thus for the efficiency. A number of three or four sealing strips and corresponding recesses per rotary piston may be particularly suitable in order to achieve a high efficiency.

The sealing strips protrude over the respective sprocket preferably by a radial distance, which is between 5% and 30%, in particular between 10% and 25%, of a radius of the sprocket. This radius can be measured from the center of the rotary piston to the outer periphery of the associated ring gear. The protruding radial distance influences the size of a deformation of the sealing performance and thus influences the sealing properties. In addition, the protruding radial distance is decisive for the volume of exhaust gas, which is conveyed past the associated rotary piston, and thus crucial for compression ratios and the efficiency of the internal combustion engine. It has been found that a good seal and high efficiency can be achieved with the aforementioned values.

A radial size of teeth of the sprockets is preferably at most 20%, preferably at most 15%, of a radius of the sprocket. Hereby, an exhaust gas flow between the two sprockets is sufficiently far reduced.

Larger teeth could also have adverse effects on the flow of exhaust gas, depending on the exhaust gas. The radius of the ring gear may be defined by the distance from its center to its outer periphery, so the outer end of the teeth.

The ignition chamber, which may also be referred to as a combustion chamber, is a closable space in which fuel is ignited. Depending on the type of fuel and an air introduction may be provided in the ignition chamber, such as when gasoline is burned. Depending on the design of the closable inlet and closable outlet, the ignition chamber is not necessarily completely closed at a certain time.

In principle, the internal combustion engine can serve any purpose in which energy from the combustion of fuel is to be used. For example, the internal combustion engine may be part of a vehicle or a stationary plant, such as a power plant.

A motor unit is usually described here with two rotary pistons. In principle, however, other rotary pistons can be present in the same interior. In addition, the number of sealing strips and associated recesses may differ from the number described for the various embodiments.

Several motor units

• eine zweite Zündkammer, umfassend einen Einlass für zu verbrennenden Kraftstoff, einen Abgaseinlass, der mit dem Auslass der ersten Motoreinheit verbunden ist, und eine zweite Zündvorrichtung zum Entzünden von Kraftstoff in der zweiten Zündkammer,
• ein zweites Kolbengehäuse, welches einen zweiten Innenraum bildet, in dem mindestens zwei weitere Drehkolben angeordnet sind,
• einen zweiten schließbaren Einlass von der zweiten Zündkammer zum zweiten Innenraum zum Einleiten von Abgas, welches durch Verbrennung von Kraftstoff in der zweiten Zündkammer entsteht, wobei die mindestens zwei weiteren Drehkolben vom Abgas angetrieben werden,
• wobei der zweite Innenraum einen zweiten Auslass für Abgas aufweist.

An internal combustion engine according to the invention may comprise a plurality of motor units arranged in series, wherein apart from the first motor unit at least one second motor unit is present. The second motor unit may include:

• a second ignition chamber including an inlet for fuel to be combusted, an exhaust gas inlet connected to the outlet of the first engine unit, and a second ignition device for igniting fuel in the second ignition chamber,
• a second piston housing, which forms a second interior, in which at least two further rotary pistons are arranged,
• a second closable inlet from the second ignition chamber to the second internal space for introducing exhaust gas, which is produced by combustion of fuel arises in the second ignition chamber, wherein the at least two further rotary pistons are driven by the exhaust gas,
• wherein the second internal space has a second outlet for exhaust gas.

By using several motor units in succession, a higher efficiency can be achieved. After flowing through the first engine unit exhaust still has a relatively high energy, which is determined by the exhaust pressure and the exhaust gas temperature. This energy is at least partially utilized by passing the exhaust gas from the first to the second motor unit, which is referred to herein as an array in series. In the second engine unit, the remaining exhaust gas pressure can be used to drive the rotary pistons of the second engine unit, together with further exhaust gas produced by combustion of fuel in the second ignition chamber.

In an analogous manner, further motor units can follow the second motor unit, between which exhaust gas is passed on in each case. The transfer of exhaust gas from one engine unit to the next may refer to the transfer of all or a portion of the exhaust gas.

Variants concerning several motor units

There may be a drive shaft with which the rotary pistons of the plurality of motor units are coupled. In particular, in each case a first rotary piston of each motor unit can be coupled to the drive shaft, while a second rotary piston of the respective motor unit cooperates in driving the associated first rotary piston. A coupling does not have to mean a rigid connection, but can denote that a force transfer from a rotating rotary piston to the drive shaft takes place in order to drive it. By coupling a plurality of motor units relatively simple and easily constructed motor units can be used and yet on the drive shaft, a high torque can be generated.

The rotary pistons of the first motor unit can be rotationally offset with respect to their axis of rotation or with respect to the drive shaft to the rotary piston of the second motor unit. The rotary lobes of optionally existing further motor units can also be rotationally offset from the rotary pistons of the remaining or at least the adjacent ones Be motor units. A rotary offset is defined by a rotation angle which indicates a rotation angle difference between the rotary pistons of different motor units. A rotation angle difference is expressed by a different position of the sealing strips of the considered rotary pistons. For this rotational offset, in particular always that rotary piston, which faces the inlet into the corresponding interior, are taken into account. In particular, the angle of rotation may correspond to 360 ° divided by the number of motor units. By such a uniform division, a restless running of the entire internal combustion engine can be reduced.

A last one of the engine units may include an exhaust gas outlet via which at least a part of the exhaust gas is returned to an exhaust gas inlet in the first ignition chamber of the first engine unit. In particular, a symmetrical structure of equal engine units can be provided, wherein each engine unit at least partially passes exhaust gas to the next engine unit. It can be provided that each engine unit passes on a portion of the exhaust gas flowing through not to one of the engine units, but to an exhaust aftertreatment system or an exhaust system. This proportion of exhaust gas may be determined during operation in proportion to a total amount of exhaust gas in the engine units or may be determined by pressure relief valves.

An electronic control device may be present and configured to make a fuel injection into the respective ignition chambers and an activation of the associated ignition devices variably depending on a currently required power, in particular to introduce or ignite fuel either into all or only into a variably adjustable part of the engine units, wherein the remaining engine units are driven solely by exhaust gas from the previous engine units. As a result, a momentarily generated power and a momentarily generated torque are variably adjustable. In other words, a frequency at which fuel is introduced and ignited may be different for the different engine units, wherein these frequencies of the various engine units may be variably varied in time, depending on the required power or torque.

The or an electronic control device can also be set up to set ignition times of the ignition devices of different engine units in such a way that they take place one after the other, that is to say offset in time and not simultaneously. In particular, a delay V between the ignition times of different igniters may be set as V = D / n, where D is the duration between two consecutive ignition times of the same ignition device and n is the number of engine units. The quantity n may also be the number of engine units currently being used for ignition, so that both in a partial load operation (in which some of the engine units are driven only by exhaust of the previous engine units and do not burn fuel themselves) as well as in a full load operation (in which all engine units Burn fuel) a uniform distribution of the ignition timing is present. From an exactly uniform distribution of the ignition timing can be done a different correction, by which a certain position of the sealing strips is achieved at the ignition time.

If there are at least three engine units, then a last of the plurality of engine units, in particular as the only one of the plurality of engine units, can have no ignition device and no inlet for fuel to be combusted. Rotary pistons of this last engine unit are thus driven solely by exhaust gas from one or more preceding engine units. In this way, it can be achieved that exhaust gas always flows through at least two interiors of different engine units, regardless of which ignition chamber burned fuel.

Alternatively, after some or all of the engine units, the exhaust gas flow can be split so that a part of the exhaust gas is directed to the next engine unit and a part is no longer directed to one of the engine units but, for example, to an exhaust aftertreatment system.

In principle, the motor units can be positioned as desired. However, it may be preferred that the plurality of motor units are arranged one above the other in the direction of the axes of rotation of the rotary pistons. This simplifies the mechanical effort to couple the motor units with one and the same drive shaft. In addition, this makes a compact design possible, which is advantageous if the plurality of motor units are surrounded by a common heat insulation housing.

A heat-insulating housing has the advantage that the exhaust gas loses little heat energy and thus only a small proportion of the exhaust gas pressure is lost. By arranging one above the other, vibrations of the individual motor units can at least partially be compensated. However, an arrangement of the motor units can be advantageous side by side, which may depend in particular on whether a transfer of exhaust gas over a front or lateral surface of an interior of a motor unit should be made.

An electronic control device may be present and configured to perform a rotation reversal of the rotary pistons of the motor units. This may be desirable, for example, to provide a reverse gear when used in a motor vehicle. In this case, exhaust gas is conducted in the opposite direction through the respective interior of the engine units, that is from an outlet of the interior to the inlet of the same interior space. This can be achieved, in particular, by changing the opening and closing timings for the closable inlet and the closable outlet of an ignition chamber. In particular, the order is reversed in which the closable inlet and the closable outlet, which adjoin the same ignition chamber, are opened and closed. In this reversed-rotation operation, exhaust gas produced by combustion of fuel in the second ignition chamber of the second engine unit is not directed to the interior of the second engine unit, but to the interior of the first engine unit. In this operating mode, exhaust gas thus does not leave the second ignition chamber through the closable inlet of the second engine unit, but through the closable outlet of the first engine unit. In this reversed-rotation mode, the first ignition chamber is either not used to ignite fuel, or the exhaust gas and the first ignition chamber are directed to another (especially last) of the engine units.

In order to provide the reverse rotation mode of operation, it may be advantageous if the closable inlets and closable outlets are formed identically or identically. When the sealing lobes of the rotary pistons are used to open and close the closable inlets and closable outlets (as further described elsewhere in this disclosure), a rotation reversal occurs changed a rotation angle offset between rotary piston successive motor units, in particular vice versa.

At the outlet of the interior of the first piston housing there may be an outlet closing body which provides a closable connection to the ignition chamber of the second motor unit. An electronic control device may be provided and configured to activate the second ignition device while the outlet closing body of the first motor unit is closed and in particular is open during the inlet closing body of the second motor unit. Alternatively, if the inlet closing body of the second motor unit is still closed when being ignited by the second igniter, in any case, the inlet closing body of the second motor unit opens earlier than the outlet closing body of the first motor unit.

The rotary pistons are dimensioned and arranged in the interior, that they share this seal at standstill. As a result, exhaust gas can only flow through the interior space (that is to say from the ignition chamber to an outlet opening located in the interior space on one side of the rotary piston, which lies opposite the ignition chamber), when the rotary pistons are rotated. On the one hand, contact between the two rotary pistons is necessary for this seal. Through this contact little or no exhaust gas can pass between the two rotary pistons. On the other hand, a contact of the two rotary pistons to the housing inner wall is required for the seal. This contact is at least on an outwardly facing side of the respective rotary piston, which faces away from the contact area between the rotary piston. For example, each rotary piston by means of its sealing strips provide a sealing contact with the adjacent housing inner wall over an angular range of at least 150 °, preferably at least 180 ° and more preferably more than 180 °.

Numerical values given here are to be understood in such a way that deviations of 10% are recorded in addition to the exact numerical value.

The properties of the invention described as additional objective features are also to be understood as variants of the method according to the invention, and vice versa.

figure description

Fig. 1

einen Querschnitt eines Ausführungsbeispiels eines erfindungsgemäßen Verbrennungsmotors;

Fig. 2

einen vergrößerten Ausschnitt aus Fig. 1;

Fig. 3

einen Querschnitt eines weiteren Ausführungsbeispiels eines erfindungsgemäßen Verbrennungsmotors;

Fig. 4

eine schematische Darstellung eines weiteren Ausführungsbeispiels eines erfindungsgemäßen Verbrennungsmotors.

Further advantages and features of the invention will be described below with reference to the accompanying schematic figures. Herein show:

Fig. 1

a cross section of an embodiment of an internal combustion engine according to the invention;

Fig. 2

an enlarged section Fig. 1 ;

Fig. 3

a cross section of another embodiment of an internal combustion engine according to the invention;

Fig. 4

a schematic representation of another embodiment of an internal combustion engine according to the invention.

Identical and identically acting components are generally identified by the same reference numerals in the figures.

In Fig. 1 is shown schematically a cross section of an embodiment of an internal combustion engine 100 according to the invention. An enlarged section of this is in Fig. 2 shown.

Shown is a motor unit 1 of the internal combustion engine 100, wherein it comprises a plurality of motor units. The remaining motor units can be constructed the same as the one shown.

The engine unit 1 comprises an ignition chamber, not shown here, into which a fuel is introduced and ignited by means of an ignition device. From this ignition chamber reaches exhaust gas, which is the combustion of the fuel, via a closable inlet 13 into an interior 11 of a piston housing 10 of the motor unit 1. There are at least two rotary pistons 20, 30 are arranged, which are offset by the pressure of exhaust gas in rotation.

In the present case, burnt fuel or burnt fuel-gas mixture is referred to as exhaust gas. The term of the exhaust gas is to be understood broadly and is intended to include the gases or fluids which arise in an ignition of the fuel in the ignition chamber and thus cause the pressure on the rotary pistons 20, 30.

The interior 11 of the piston housing 10 is limited by a housing inner wall 18, which has two circular section-shaped portions, each one of the two rotary pistons 20, 30 surrounded. For a seal to the rotary pistons 20, 30, each of the circular section-shaped sections cover a circular section of over 180 °.

Exhaust gas flows through the interior 11 from the closable inlet 13 to a closable outlet 16, for which purpose it flows along the rotary pistons 20, 30 and causes them to rotate.

For efficient operation, the design of the rotary pistons 20, 30 is important. These are intended to provide a seal to one another and a seal to the surrounding housing inner wall 18, so that the exhaust gas can not reach the outlet 16 when the rotary pistons 20, 30 are at a standstill.

At the same time, the rotary pistons 20, 30 are to be easily drivable by the exhaust gas, that is, they are already rotating at low pressure. For these purposes, the two rotary pistons 20 and 30 have at their respective outer sides via sealing strips 25, 26, 35, 36. The outer sides can be regarded as lateral surfaces of approximately cylindrical rotary pistons 20, 30. The sealing strips 25, 26, 35, 36 preferably extend over the entire height of the inner space 11, wherein the height in the direction of rotation axes 21, 31 of the two rotary pistons 20 and 30 can extend. The axes of rotation 21, 31 extend into the plane of the drawing.

The rotary piston 20 has at least two sealing strips 25, 26. Likewise, at least two sealing strips 35, 36 are arranged on the rotary piston 30. The sealing strips 25, 26, 35, 36 project radially beyond the remaining outer circumference of the associated rotary piston 20, 30. The sealing strips 25, 26, 35, 36 are preferably received in grooves on the respective rotary piston 20, 30 and may preferably consist of a different material than the part of the rotary piston 20, 30, in which the grooves are formed. In particular, the sealing strips 25, 26, 35, 36 may consist of a deformable material. This may be, for example, rubber, resin or a plastic. As a result, the sealing strips 25, 26, 35, 36 can be slightly deformed by countercurrent exhaust gas and pressed against the housing inner wall 18. This is a particularly good seal to the housing inner wall 18 reached. In principle, the sealing strips 25, 26, 35, 36 but also consist of a rigid material, such as metal. Alternatively or additionally, the sealing strips 25, 26, 35, 36 may be accommodated with some freedom in their associated grooves, with which the exhaust pressure, the sealing strips 25, 26, 35, 36 can easily tilt. As a result, in principle, the sealing strips 25, 26, 35, 36 are also pressed sealingly against the housing inner wall 18.

In order to largely rule out an exhaust gas flow between the rotary pistons, the two rotary pistons 20, 30 are arranged in the inner space 11 in such a way that they touch each other. For this purpose, the rotary pistons 20, 30 at their respective outer circumference also each have a toothed rim 23, 33, which is rigidly connected to the remaining part of the associated rotary piston 20, 30. The two sprockets 23, 33 are sized and arranged so that they mesh. As a result, both sprockets 23, 33 rotate together and form hardly any voids between each other. Exhaust gas can therefore hardly pass between the two sprockets 23, 33.

In addition, the rotary pistons 20 and 30 at their respective outer periphery recesses 27, 28 and 37, 38. The number of recesses 27, 28 of the first rotary piston 20 is equal to the number of sealing strips 35, 36 of the second rotary piston 30 is selected. Similarly, the number of recesses 37, 38 of the second rotary piston 30 is equal to the number of sealing strips 25, 26 of the first rotary piston 20 is selected. In addition, the recesses 27, 28, 37, 38 and the sealing strips 25, 26, 35, 36 arranged on the two rotary pistons 20, 30 so that upon rotation of the two rotary pistons 20 and 30, the sealing strips 25, 26 of the first rotary piston 20 straight on the recesses 37, 38 of the second rotary piston 30 meet. Likewise, the sealing strips 35, 36 of the second rotary piston 30 meet straight on the recesses 27, 28 of the first rotary piston 20. A size and shape of the recesses is selected so that the sealing strips in these, in particular sealing, can be accommodated.

Like the sprockets 23, 33 cause the sealing strips 25, 26 35, 36 together with the recesses 27, 28, 37, 38, that the exhaust gas can hardly pass between the two rotary pistons.

Regardless of a current rotational position is also always one of the sealing strips 25, 26 35, 36 of each rotary piston 20, 30, a seal to the housing inner wall 18 provide. For this purpose, a rotation angle is relevant, via the same sealing strip 25, 26 35, 36 causes a seal to the housing inner wall 18. This rotation angle can, as in Fig. 1 may be greater than 180 ° and, for example, between 185 ° and 240 °. For this purpose, the housing wall 18 at each of the rotary pistons has a circular section shape, this shape forms a circular section of greater than 180 °, that forms more than a semicircle.

The inclusion of the sealing strips 25, 26 35, 36 in their associated grooves is closer in Fig. 2 recognizable. By way of example for all sealing strips 25, 26 35, 36, the sealing strip 35 is shown there in its cross section. The sealing strip 35 may be shaped like a profile, that is over its length (in particular in the direction of the axis of rotation 31) have the same cross-sectional shape. As shown, the cross-sectional shape forms a sliding block. In this, a collar 35C is formed toward the inner end of the sealing strip 35. This engages in a T-shaped depression / groove. This prevents that the sliding block can unintentionally come loose in the radial direction from the groove of the rotary piston. Inserting and removing the sliding block 35 is possible in the longitudinal direction, that is to say in the direction of the axis of rotation 31. Due to the formation as sliding blocks, the sealing strips are on the one hand easy to attach. On the other hand, replacement is also simplified. This is significant because it may come to a gradual abrasion of the sealing strips 25, 26, 35, 36 due to the sealing contact with the housing inner wall 18 and so an exchange may be required.

As in Fig. 1 shown, pushes the exhaust gas in the interior 11 against the rotary pistons 20, 30 and those sealing strips 25, 35, which face in the current rotational position of the rotary piston 20, 30 of the connection to the ignition chamber 40. By this pressure, the rotary pistons 20, 30 rotate in the direction of Fig. 1 drawn arrows.

For the rotation and in particular the sealing effect of the sealing strips 25, 35, their shape is important. This will be closer with respect to Fig. 2 described. There, a sealing strip 35 is shown, which protrudes radially from the toothed rim 33. The sealing strip 35 has a point of maximum radial extent, or an edge extending into the plane of the drawing (or extending in the direction of the axis of rotation 31). From this edge, the sealing strip 35 has a surface 35A or exhaust gas contact side 35A, which faces the incoming exhaust gas (this applies to Rotational positions in which the sealing strip 35 the housing inner wall 18 contacted). On the other side of said edge, the sealing strip 35 has another surface 35B, which is also referred to as the back 35B. The rear side 35 B does not face the inflowing exhaust gas when the sealing strip 35 contacts the housing inner wall 18.

The exhaust gas contact side 35A has a recess or a concave shape, while the rear side 35B has an outwardly curved or convex shape. As a result, the outer end of the sealing strip 35, so the radially outermost part deformed by the counterflowing exhaust gas transversely or approximately perpendicular to the radial direction. Thus, the sealing strip 35 is pressed against the housing inner wall 18. In Fig. 2 the lower end of the sealing strip 35 is deformed approximately to the left and thus against the housing inner wall 18.

Advantageously, a particularly good seal can be produced thereby, but without generating an unduly high friction between the sealing strips and the housing inner wall. Even with a relatively low exhaust gas pressure, the rotary pistons can therefore advantageously be set in rotation. Thus, exhaust gases with low pressure can be used for energy use.

The generated rotational energy can be used in principle any way. In particular, it can be converted into electrical energy, such as with a generator. If the internal combustion engine is part of a vehicle, the electrical energy can be fed into an electrical system of the motor vehicle and / or stored in an electrochemical battery or other storage means. Alternatively, the rotational energy can also be transmitted to drive wheels of the vehicle.

At the in Fig. 1 embodiment shown, the inlet 13 and outlet 16 are located on an end face of the interior 11. About movable closing body, the inlet 13 and the outlet 16 can be opened and closed to initiate exhaust gas from the ignition chamber or exhaust gas from the interior 11. The arrangement of the inlet 13 and outlet 16 may be such that they are swept by the sealing strips 25, 26, 35, 36. Thus, the sealing strips 25, 26, 35, 36 as a closing body for the inlet 13 and / or the outlet 16 serve. The sealing strips 25, 26, 35, 36 thus provide not only the previously described seal to a lateral surface of the interior 11, but also to the bottom and the ceiling of the interior 11, which are referred to as end faces. Alternatively, the inlet 13 and outlet 16 can also be located on the lateral surfaces, wherein also optionally by the sealing strips 25, 26, 35, 36 opening and closing of the inlet 13 and outlet 16 can be effected.

A further embodiment of an internal combustion engine according to the invention is shown schematically in FIG Fig. 3 shown. This differs from the execution of the Fig. 1 in the inlet 13, which connects the ignition chamber 40 with the interior 11. at Fig. 3 is provided as a movable closing body at the inlet 13, a rotatably mounted slot roller 45. This comprises one or more slots which, depending on the rotational position, provide a passage for exhaust gas to the interior 11 or prevent a passage of exhaust gas to the interior 11. Thereby, a desired pressure to the rotary piston 20, 30 can be better adjusted and times for the opening and closing of the inlet 13 can be precisely and variably adjustable. The slot roller 45 is preferably coupled to the rotary pistons so that there is a fixed but optional adjustable relationship between a rotational position of the slot roller 45 and the rotary piston 20, 30.

At the ignition chamber 40, a schematically illustrated fuel inlet 15 is present, via which fuel, depending on the design as a fuel-gas mixture, is introduced into the ignition chamber 40. For example, the fuel inlet 15 may include one or more injectors. In addition, the fuel inlet 15 may comprise separate openings for introducing gas or fresh air (without fuel).

The ignition chamber 40 and the inner space 11 are formed here in separate housings 10 and 41. The two housings 10, 41 can also be spaced apart as long as an exhaust pipe is made possible between them. Preferably, no components are present between the rotary pistons 20, 30 and the ignition chamber 40, which would use the energy released by the combustion, whereby the rotary piston engine described here can use the significant proportion of the energy released by the combustion.

In the example of Fig. 3 At the outlet 16 of the interior 11, a slot roll is used to open and close the outlet 16. Instead of slot rollers and rollers can be used with a different opening shape. In the illustrated example, the axes of rotation of the slot roller (s) are parallel to the axes of rotation of the rotary pistons 20, 30. This is particularly useful when the inlet 13 and the outlet 16 are located on the lateral surfaces of the interior 11. In an arrangement of the inlet 13 and outlet 16 at the end faces, the axis of rotation of a slot roll may also be transverse or perpendicular to the axes of rotation of the rotary pistons 20, 30.

Fig. 4 schematically shows a structure of an internal combustion engine according to the invention, with a plurality of motor units, of which a first motor unit 1 and a second motor unit 101 are exemplified. The first motor unit 1 is here as well Fig. 1 described designed. The second motor unit 101 can in principle be constructed in the same way. In Fig. 4 are the two motor units 1, 101 shown side by side only for ease of illustration; Preferably, the motor units 1, 101 in the direction of the axes of rotation 21, 31 stacked one above the other.

Components to the second motor unit 101 are designated by reference numerals which are larger by one hundredth than reference numbers of like components of the first motor unit 1. Accordingly, the second motor unit comprises in particular: 120 and 130: rotary pistons; 121 and 131: axes of rotation; 125, 126, 135: sealing strips; 127, 137 and 138: pits; 118: housing inner wall; 123 and 133: sprockets; 110: rotary piston housing; 111: interior; 113 closable inlet; 116: closable outlet.

The second motor unit 101 likewise includes an ignition chamber, not shown here. The ignition chamber of the second motor unit 101 may be constructed as described for the ignition chamber of the first motor unit 1. In particular, the ignition chamber of the second engine unit includes a fuel inlet and let-in fuel is ignited and burned via an igniter. Resulting exhaust gas is left through the inlet 113 into the inner space 111 to drive the rotary pistons 120, 130 of the second motor unit 101.

As a particular feature, the ignition chamber of the second engine unit 101, which will be referred to as a second ignition chamber hereinafter, also has an exhaust gas inlet connected to the outlet 16 of the first engine unit 1. Exhaust gas that has passed through the interior 11 of the first engine unit 1 is thus (at least partially) conducted into the ignition chamber of the second engine unit 101. As a result, we still use an existing exhaust gas pressure of the exhaust gas of the first motor unit 1 for driving the rotary pistons 120, 130 of the second motor unit 101. The efficiency of the internal combustion engine is also increased because the heat energy of the exhaust gas of the first motor unit 1 is used for the second motor unit 101.

A connection from the outlet 16 to the exhaust gas inlet of the second ignition chamber may be constructed like a tube. A simple and therefore less error-prone construction provides that a single closing body is provided for opening and closing this connection. For this purpose, as described above, the outlet 16 can be designed as a closable outlet, which can be closed by, for example, the sealing strips or a rotating slot roller.

The plurality of motor units 1, 101 arranged one above the other can be coupled to the same drive shaft, so that the summed power of the motor units 1, 101 can be used together.

Depending on the currently desired power (or torque), it may be provided that within a cycle (which may be defined as the duration between two fuel ignitions of the same engine unit) only a certain portion of the engine units perform a fuel injection and ignition. The higher the currently desired power, the more engine units will fuel and ignite.

With the internal combustion engine according to the invention, a particularly high efficiency can be generated, in particular by the sealing strip design and the cascading of several rotary piston engine units, with a robust construction.

Claims (15)

Internal combustion engine, comprising
a first motor unit (1) with a first ignition chamber (40) comprising a fuel inlet (15) for fuel to be combusted and an ignition device (42) for igniting fuel in the first ignition chamber (40), - A first piston housing (10) which forms an interior space (11) in which at least two rotary pistons (20, 30) are arranged, - a closable inlet (13) from the first firing chamber (40) to the interior (11) for introducing exhaust gas resulting from the combustion of fuel in the first firing chamber (40), the at least two rotors (20, 30) from the exhaust are driven, - wherein the interior (11) of the first piston housing (10) has an outlet (16) for exhaust gas, - Wherein each rotary piston (20, 30) on its outer circumference at least two sealing strips (25, 26, 35, 36) and at least two recesses (27, 28, 37, 38), wherein the shapes of the recesses (27, 28, 37 , 38) and the sealing strips (25, 26, 35, 36) are selected for engaging the sealing strips (25, 26, 35, 36) of in each case one of the rotary pistons (20, 30) in the recesses (27, 28, 37, 38) of the respective other rotary piston (20, 30), - Wherein the sealing strips (25, 26, 35, 36) in the radial direction of the respective rotary piston (20, 30) for sealingly contacting a housing inner wall (12) are dimensioned. Internal combustion engine according to claim 1,
characterized,
that in each case an inlet-closing body is provided on each closable inlet (13) which for opening and closing the inlet (13) and is movable with the rotary pistons (20, 30) is coupled. Internal combustion engine according to claim 2,
characterized,
in that the inlet closing body is formed by the sealing strips (25, 26, 35, 36). Internal combustion engine according to claim 3,
characterized,
in that the closable inlet (13) is formed in an end face of the interior (11) and
that a contact surface of the sealing strips (25, 26, 35, 36) to the end face is greater than a contact surface of the sealing strips (25, 26, 35, 36) to a lateral surface of the inner space (11). Internal combustion engine according to claim 3 or 4,
characterized,
that a size of the contact surfaces of the sealing strips (25, 26, 35, 36) is defined to the front side characterized in that the sealing strips (25, 26, 35, 36) include a notch towards the end face, which leaves free the closable inlet (13), and or
in that the sealing strips (25, 26, 35, 36) have a broadening towards the end face, by means of which the contact surface with the end face is enlarged. Internal combustion engine according to one of claims 1 to 5,
characterized,
in that the sealing strips (25, 26, 35, 36) comprise a deformable material so that they can be pressed sealingly against the housing inner wall (12) by the exhaust gas. Internal combustion engine according to one of claims 1 to 6,
characterized,
that each of the sealing strips (25, 26, 35, 36) at a rotational angle position of the associated rotary piston (20, 30), wherein said sealing strip (25, 26, 35, 36) the Housing inner wall (12) contacted, having an exhaust gas contact side (35A), which faces incoming exhaust gas, and
that the exhaust gas contact side (35A) has a concave shape. Internal combustion engine according to one of claims 1 to 7,
characterized,
in that each of the sealing strips (25, 26, 35, 36) has a rear side (35B) which lies opposite the exhaust gas contact side (35A) and at a rotational angle position of the associated rotary piston (20, 30), at which this sealing strip (25, 26, 35 , 36) contacted the housing inner wall (12), facing non-inflowing exhaust gas, and
that the back (35B) is convex. Internal combustion engine according to one of claims 1 to 8,
characterized,
that each of the rotary pistons (20, 30) on its outer periphery a ring gear (23, 33),
that the rotary pistons (20, 30) are arranged so that their sprockets (23, 33) interlock, and
that the sealing strips (25, 26, 35, 36) in the radial direction of their respective rotary piston (20, 30) project further outwards than the respective sprocket (23, 33). Internal combustion engine according to one of claims 2 to 9,
characterized,
in that each inlet closing body comprises in each case a rotatably mounted roller (45) which has a passage, so that, depending on the rotational position of the roller (45), the associated inlet (13) is opened or closed. Internal combustion engine according to claim 10,
characterized,
in that the roller (45) is formed as a slot roller (45), the passage of which is a slot, wherein a cross-sectional area of the slot leads to the interior space (11) other size has as a cross-sectional area of the slit toward the ignition chamber (40). Internal combustion engine according to one of claims 1 to 11,
characterized,
in that a plurality of motor units arranged in series are provided, which comprise, in addition to the first motor unit (1), at least one second motor unit (101),
that the second motor unit (101) comprises: a second ignition chamber (140) comprising a fuel inlet (15) for fuel to be combusted, an exhaust inlet connected to the outlet (16) of the first engine unit (1), and a second igniter (140) for igniting fuel in the second ignition chamber (140), a second piston housing (110) which forms a second interior space (111) in which at least two further rotary pistons (120, 130) are arranged, a second closable connection (113) between the second internal space (111) and the second ignition chamber (140) for introducing exhaust gas, which is produced by combustion of fuel in the second ignition chamber (140), wherein the at least two further rotary pistons (120, 120) 130) are driven by the exhaust gas, - Wherein the second interior (111) has a second outlet (116) for exhaust gas. Internal combustion engine according to claim 12,
characterized,
that the plurality of motor units (1, 101) in the direction of the axes of rotation of the rotary pistons (20, 30, 120, 130) are arranged one above the other,
that the plurality of motor units (1, 101) are surrounded by a common heat insulating housing,
that a drive shaft is present, with which the rotary pistons (20, 30, 120, 130) of the plurality of motor units (1, 101) are coupled. Internal combustion engine according to one of claims 12 to 13,
characterized,
in that an outlet closing body is provided at the closable outlet (16) of the interior (11) of the first piston housing (10),
that an electronic control means is provided adapted and to activate the second igniter (142), while the AuslassSchließkörper the first motor unit (1) is closed, and in particular during the inlet-closing body of the second motor unit (101) is open. Method for operating an internal combustion engine,
wherein a first engine unit (1) of the internal combustion engine comprises a first ignition chamber (40) and a first piston housing (10) forming an internal space (11) in which at least two rotary pistons (20, 30) are arranged, the method comprising: Introducing fuel to be burned into the first ignition chamber (40), Ignition of fuel in the first ignition chamber (40) by means of an ignition device (42), - Opening and closing a closable inlet (13) from the first ignition chamber (40) to the interior (11) to introduce exhaust gas, which is produced by combustion of fuel in the first ignition chamber (40), wherein the at least two rotary pistons (20, 30 ) are driven by the exhaust gas, - discharging the exhaust gas from the interior (11) of the first piston housing (10) through an outlet (16) on the interior (11), - Wherein each rotary piston (20, 30) on its outer circumference at least two sealing strips (25, 26, 35, 36) and at least two recesses (27, 28, 37, 38), wherein the shapes of the recesses (27, 28, 37 , 38) and the sealing strips (25, 26, 35, 36) are selected for engaging the sealing strips (25, 26, 35, 36) of in each case one of the rotary pistons (20, 30) in the recesses (27, 28, 37, 38) of the respective other rotary piston (20, 30), - Wherein the sealing strips (25, 26, 35, 36) in the radial direction of the respective rotary piston (20, 30) for sealingly contacting a housing inner wall (12) are dimensioned.

Images