DE102020125196A1 - Reciprocating machine and device - Google Patents

Abstract

The invention relates to a reciprocating piston machine (1) with a housing (2), with at least one crankshaft (4) which is mounted on the housing (2) so that it can rotate about an axis of rotation (5) relative to the housing (2), with at least a cylinder (3), and with at least one translationally movable piston (7) accommodated in the cylinder (3), which is coupled in an articulated manner to the crankshaft (4) via a connecting rod (10), comprising a second crankshaft (20) which is rotatably mounted on the first crankshaft (4) relative to the first crankshaft (4) about a second axis of rotation (21) spaced apart from the axis of rotation (5) and running parallel to the axis of rotation (5) and has a crank pin (22), with which the piston (7) is articulated via the connecting rod (10).

Description

The invention relates to a reciprocating engine according to the preamble of patent claim 1. The invention also relates to a device with at least one such reciprocating engine.

Reciprocating machines are already well known from the general state of the art. Such a reciprocating piston machine is usually used as an internal combustion engine or as an internal combustion engine in order to drive a motor vehicle such as a motor vehicle.

Furthermore, the EP 2 633 166 B1 a machine combination with an internal combustion engine and a generator for charging the battery of a hybrid drive.

The object of the present invention is to create a reciprocating piston machine and a motor vehicle with such a reciprocating piston machine, so that a particularly high degree of efficiency of the reciprocating piston machine can be achieved.

According to the invention, this object is achieved by a reciprocating piston engine having the features of patent claim 1 and by a motor vehicle having the features of patent claim 11 . Advantageous configurations of the invention are the subject matter of the dependent patent claims.

A first aspect of the invention relates to a reciprocating piston machine for a motor vehicle, in particular for a motor vehicle which is preferably designed as a passenger car. This means that the reciprocating piston engine is preferably used for or in a motor vehicle. In particular, the reciprocating piston engine is designed as an internal combustion engine, also designed as an internal combustion engine, motor or internal combustion engine, which can be operated in a fired mode. In this case, the motor vehicle can be driven by means of the reciprocating piston engine, in particular in the fired operation.

The reciprocating piston machine has a housing, which can be a crankcase, for example. In addition, the reciprocating piston machine includes a crankshaft, which is also referred to as the first crankshaft and is mounted on the housing such that it can rotate about an axis of rotation, also referred to as the first axis of rotation, relative to the housing. This means that the crankshaft is rotatable about the first axis of rotation relative to the housing, while the crankshaft is mounted on the housing. The crankshaft is, for example, an output shaft of the reciprocating engine, which can provide at least one torque for driving the motor vehicle via its output shaft. the reciprocating piston machine also has at least one cylinder, which is delimited or formed, for example, by the housing, in particular directly. Thus, for example, the housing has the cylinder. For example, the cylinder is formed or delimited, in particular directly, by a cylinder wall, in particular of the housing. In particular, the cylinder wall has a lateral surface on the inner circumference, by which the cylinder is preferably directly delimited. The reciprocating piston engine also includes at least one piston which is accommodated in the cylinder in a translationally movable manner. This means that the piston in the cylinder can be moved translationally relative to the cylinder wall or relative to the housing. The piston is coupled in an articulated manner to the crankshaft via a connecting rod, as a result of which, for example, translational movements of the piston in the cylinder can be converted into a rotary movement or rotation of the crankshaft relative to the housing, in particular in a first direction of rotation.

For example, the cylinder and the piston each partially delimit a combustion chamber of the reciprocating piston engine, with combustion processes taking place in the combustion chamber in particular when the reciprocating piston engine is in the fired operation. The piston, which can be moved in a translatory manner in the cylinder between a bottom dead center (UT) and a top dead center (OT), is driven by these combustion processes, that is to say moved in a translatory manner. Since the piston is articulated to the first crankshaft, the first crankshaft is driven by driving the piston and is thus rotated about the axis of rotation, in particular in the first direction of rotation, relative to the housing. As a result, the reciprocating piston machine can provide the aforementioned torque for driving the motor vehicle via its crankshaft. The connecting rod is, on the one hand, at least indirectly articulated to the piston and, on the other hand, at least indirectly articulated to the first crankshaft. For example, the connecting rod is coupled to the piston in an articulated manner via a piston pin. For example, respective longitudinal areas of the piston pin are accommodated in respective receptacles of the connecting rod and the piston, as a result of which the connecting rod is coupled to the piston in an articulated manner. The articulated coupling of the connecting rod to the piston means in particular that the connecting rod can be pivoted relative to the piston, in particular about a pivot axis is pivotable while the connecting rod is coupled to the piston. The pivot axis preferably runs parallel to the first axis of rotation.

In order to be able to achieve a particularly high degree of efficiency of the reciprocating-piston machine, also referred to as a piston engine and designed as a piston engine, it is provided according to the invention that the reciprocating-piston machine has a second crankshaft, which is designed in particular separately from the first crankshaft and which rotates about a second axis of rotation relative to the first crankshaft is rotatably mounted on the first crankshaft. The second axis of rotation is spaced apart from the first axis of rotation, with the second axis of rotation running parallel to the first axis of rotation. Thus, the second crankshaft can rotate about the second axis of rotation relative to the first crankshaft or the second crankshaft can be rotated about the second axis of rotation relative to the first crankshaft, while the second crankshaft is mounted on the first crankshaft or while the second crankshaft is connected to the first crankshaft is connected or coupled. In addition, the second crankshaft has a crank pin, with which the piston is coupled in an articulated manner via the connecting rod. The crank pin and the articulated coupling of the piston to the crank pin via the connecting rod mean in particular the following: the crank pin or its longitudinal axis, in particular the longitudinal center axis, is preferably spaced apart from the axes of rotation and runs parallel to the axes of rotation. The connecting rod, which on the one hand is articulated to the piston, is on the other hand articulated to the crankpin, in particular in such a way that the connecting rod is articulated, in particular rotatable or pivotable, on or on the crankpin, in particular in such a way that the connecting rod has a second pivot axis relative to the Crank pin is pivotable, while the connecting rod coupled or connected to the crank pin, that is, is mounted on the crank pin.

The second pivot axis is spaced apart from the first pivot axis, for example, it being possible for the second pivot axis to run parallel to the first pivot axis. For example, the second pivot axis coincides with the aforementioned longitudinal axis or longitudinal center axis. Since the first axis of rotation is spaced apart from the second axis of rotation and runs parallel to the second axis of rotation, the axes of rotation are at a first distance from one another, running perpendicularly to the axes of rotation. In addition, since the second pivot axis is spaced from the pivot axes and preferably parallel to the pivot axes, the second pivot axis and the second pivot axis have a second spacing perpendicular to the second pivot axis and perpendicular to the second pivot axis. The first distance is a first radius of a first circle centered on the first axis of rotation, wherein when the first crankshaft is rotated about the first axis of rotation relative to the housing, the second axis of rotation is moved along the first circle describes or departs. The second distance is a second radius of a second circle centered on the second axis of rotation. If the second crankshaft is now rotated about the second axis of rotation relative to the first crankshaft, the second pivot axis is moved along the second circle or the second pivot axis describes the second circle or travels the second circle. The second circle in turn moves itself because its center is on the radius of the first circle, i.e. like a wheel that rolls in a ring gear. As a result, crank kinematics or a crank mechanism comprising at least the crankshaft, the connecting rod and the piston can be created, so that a particularly high or higher degree of efficiency can be achieved compared to conventional reciprocating piston machines. As a result, the fuel consumption and thus the CO ₂ emissions of the reciprocating engine can be kept particularly low.

The invention is based in particular on the following findings and considerations. The efficiency of a reciprocating piston engine designed in particular as an internal combustion engine is essentially determined by two process variables: A first of the process variables is the length of the expansion path that is covered, for example, by the piston during an expansion stroke, also known as a power stroke, of the reciprocating piston engine, which is preferably designed as a four-stroke engine . The second process variable is the piston mean pressure or the value of the integration via pdV, caused by the maximum pressure pmax in the combustion chamber and the minimum pressure pmin in the combustion chamber - and thus ultimately by the so-called mean pressure p_mean. The mean pressure p_medium, also referred to as mean piston pressure or combustion chamber pressure, is usually technically and conceptually limited by the physical properties of a fuel that is used to operate the reciprocating piston engine in the fired mode. In the fired operation, at least a quantity of the liquid or gaseous fuel, for example, is introduced into the combustion chamber, in particular injected directly, during a respective working cycle of the reciprocating piston engine, which extends, for example, over exactly 720 crank angle degrees. As a result, the combustion chamber is supplied with fuel. In addition, air is introduced into the combustion chamber, with the air and fuel forming a fuel-air mixture, also simply referred to as a mixture. mixture is generated. The fuel-air mixture is burned within the respective working cycle, so that the respective combustion process occurs. In other words, the mixture is burned as part of the respective combustion process, as a result of which the piston and, via the piston and the connecting rod, the first crankshaft, which functions as the output shaft, are driven.

Otto fuel or gasoline can be used as the fuel. Thus, the reciprocating engine can be designed as a gasoline or Otto engine. With regard to petrol, mean piston pressure is limited by its knock resistance. It is also conceivable to use diesel fuel as the fuel, so that the reciprocating piston machine can be designed as a diesel engine, for example. While the mixture is ignited by spark ignition in the petrol engine, the mixture is ignited by self-ignition in the diesel engine. With regard to diesel fuel or the diesel engine, the mean piston pressure is limited by the pressure or the temperature of the self-ignition. Both limits usually make it impossible to increase the maximum pressure or the maximum temperature, in particular with regard to the so-called Carnot efficiency, without significant changes. Against this background, the invention makes it possible to increase the compression compared to conventional solutions, if possible up to the self-ignition limit, as a result of which a particularly high efficiency of the reciprocating piston engine can be achieved.

With a respective, complete rotation of the crankshaft, it comes into different rotational positions, which are also referred to as crank angles, crank angle positions or degree crank angles. Compared to conventional solutions, the invention now enables the maximum compression of the mixture in the cylinder or in the combustion chamber to be shifted to a rotational position or to a crank angle which lies behind the top dead center of the piston and/or behind a top dead center which is only through Use of the first crankshaft and thus would be feasible in conventional reciprocating engines. In particular, such a post-compression of the mixture in the cylinder can be realized by the invention, with the post-compression before the top dead center of the piston, ie within the respective working cycle following the top dead center of the piston.

In order to be able to achieve particularly efficient operation of the reciprocating piston machine, one embodiment of the invention provides that the second crankshaft is coupled to the housing, in particular in a form-fitting manner, such that the first crankshaft rotates about the first axis of rotation relative to the housing rotation of the second crankshaft about the second axis of rotation relative to the housing and relative to the first crankshaft results. In other words, it is preferably provided that the second crankshaft is coupled, in particular directly, to the housing in such a way that when the first crankshaft is rotated about the first axis of rotation relative to the housing, the second crankshaft results via the second axis of rotation is rotated relative to the housing and relative to the first crankshaft, and vice versa. In particular, defined rotational positions or rotational positions of the crankshafts relative to one another can be ensured in this way, so that particularly effective and efficient operation can be achieved. In particular, during operation of the reciprocating piston engine, the primary, first crankshaft KW has only one speed, namely about the first axis of rotation relative to the housing. The secondary, second crankshaft has two speeds, namely, firstly a quasi-translational rotational movement with which it circles the axis of rotation of the primary crankshaft, which corresponds to the speed of the primary crankshaft, and secondly a self-rotational speed around its own, second axis of rotation, which is caused by a rolling movement a corresponding radius, for example relating to the first axis of rotation, or can be dimensioned by corresponding radii in relation to the rotational speed of the primary crankshaft.

A further embodiment is characterized in that the second crankshaft is coupled to the housing, in particular in a form-fitting manner, in such a way that a rotation of the first crankshaft around the first axis of rotation relative to the housing in the first direction of rotation results in a rotation around the second axis of rotation relative to the housing and relative to the first crankshaft results in rotation of the second crankshaft in the opposite direction to the first direction of rotation, in the second direction of rotation. For example, while the first crankshaft rotates about the first axis of rotation in the first direction of rotation during fired operation of the reciprocating piston engine, the second crankshaft rotates about the second axis of rotation relative to the housing and relative to the first crankshaft in the second direction of rotation, which is the first Direction of rotation is opposite.

To put it another way, the directions of rotation are opposite or contradictory, which means that the reciprocating piston machine has a particularly high degree of efficiency in a very simple manner can be provided. Furthermore, it is conceivable that the rotations or speeds of the crankshafts are rectified. In other words, if, for example, the primary crankshaft rotates in a first of the directions of rotation, the axis of rotation of the secondary crankshaft orbits the primary crankshaft in the first direction of rotation, the secondary crankshaft rotates in the second direction of rotation, thus the secondary crankshaft rotates about its own Axis of rotation in the second direction of rotation, in particular when using the ring gear and thus a ring gear toothing instead of a spur gear or a spur gear toothing. In other words, it is conceivable that the second crankshaft is coupled to the housing, in particular in a form-fitting manner, such that a rotation of the first crankshaft about the first axis of rotation relative to the housing in the first direction of rotation results in a rotation about the second axis of rotation relative to the Housing and relative to the first crankshaft in the first direction of rotation occurring rotation of the second crankshaft results.

In order to be able to achieve a particularly high level of efficiency and in particular the post-compression described above, it is provided in a further embodiment of the invention that the second crankshaft is coupled to the housing, in particular in a form-fitting manner, that the second crankshaft then moves when the the first crankshaft rotates at a first speed about the first axis of rotation, the second crankshaft rotates about the second axis of rotation at a second speed, which is an integral multiple of half the first speed.

As described above, the secondary crankshaft has two speeds: a web speed about the first axis of rotation, particularly relative to the housing, and a self-rotation or intrinsic rotational speed about the second axis of rotation, particularly relative to the first crankshaft. Kinematics are preferably provided such that the intrinsic rotational speed of the secondary, second crankshaft over, in particular precisely, two, in particular complete, revolutions of the primary, first crankshaft, taking place around the first axis of rotation, itself, in particular precisely, one intrinsic rotation or complete revolution, in particular around the second axis of rotation, or a higher even value (2, 3, 4, 5, 6, 7, 8, 9 etc.).

It is also conceivable that when the first crankshaft rotates at the first speed about the first axis of rotation, the second crankshaft rotates the second crankshaft about the second axis of rotation at a second speed, which is an integer multiple of half the first speed .

It has proven to be particularly advantageous if the second speed is at least or exactly four times the first speed. In other words, the second speed is at least or exactly four times the first speed. A particularly efficient operation can be ensured in this way. With the odd and/or integer multiples or integer multiples mentioned above, in particular half of the first speed, the second speed would be, for example, 1.5 times the first speed, or 2.5 times etc. Then it can the piston stroke course is “tilted” via an angular offset or offset in relation to the crank angle of the first, primary crankshaft KW angle or x_KW, so that the compression path and expansion path are of different sizes.

In a further, particularly advantageous embodiment of the invention, the reciprocating piston machine has at least one first gear wheel provided on the housing. The first gear has a first set of teeth. For example, the first gear is designed as a spur gear. In addition, the reciprocating piston machine has a second gear wheel which is provided on the second crankshaft and which meshes directly with the first gear wheel. This means, in particular, that the teeth mesh directly with one another. Due to the fact that gears are in mutual engagement, the second crankshaft is coupled to the housing, in particular directly and in a form-fitting manner. The coupling of the second crankshaft to the housing is not to be understood as meaning a connection of the second crankshaft to the housing fixed to the housing, but rather a coupling in the sense of a kinematically guided movement.

The gears enable an advantageous, slip-free or low-slip rolling movement or coupling of the second, secondary crankshaft with the housing. Furthermore, another coupling is conceivable as an alternative or in addition, e.g. a frictional roll-off or coupling between the housing and the second crankshaft.

In order to ensure defined rotational positions of the crankshafts relative to one another and thus to be able to implement particularly efficient operation, it is provided in a further embodiment of the invention that the first gear wheel is non-rotatably connected to the housing. In particular, the first gear wheel is arranged coaxially to the first axis of rotation. It is conceivable that the first gear wheel is formed separately from the housing and is connected to the housing in a rotationally fixed manner. Furthermore, it is conceivable that the first gear is formed integrally with the housing. The first gear wheel is preferably fixed to the housing in such a way that rotational and translational relative movements between the first gear wheel and the housing do not take place. Consequently, the first gear wheel is preferably fixed to the housing, both rotationally and translationally.

In a further embodiment of the invention, provision is made for the first gear wheel to be rotatable relative to the housing. For example, the first gear can be rotated, in particular by at least one discrete angular offset, into different rotational positions relative to the housing and fixed in the rotational positions relative to the housing. For example, the first gear may be rotated about its own longitudinal axis and preferably relative to the axis of rotation of the primary crankshaft.

A further embodiment is characterized in that the first gear wheel is designed as a ring gear. As a result, the gears can mesh with one another in a particularly advantageous and space-saving manner, so that the crankshafts are particularly advantageously coupled to one another in terms of movement. The first gear wheel can, for example, have a conical toothing or can be designed as a bevel gear, which could lead to simple assembly. Furthermore, the first gear can have spur gearing, in particular axially, not or also radially, and can therefore be designed as a spur gear. Mixed forms are conceivable. In particular, the first gear can be a bevel gear or another gear.

In a further embodiment of the invention, it is provided that the second gear wheel is connected in a rotationally fixed manner to the second crankshaft. For example, the second gear wheel is arranged coaxially to the second axis of rotation. It is conceivable that the second gear wheel is formed separately from the second crankshaft and is connected to the second crankshaft in a torque-proof manner. However, it has proven to be particularly advantageous if the second gear wheel is designed in one piece with the second crankshaft. This ensures a particularly high level of efficiency.

A second aspect of the invention relates to a device which has at least one reciprocating piston machine according to the first aspect of the invention. Advantages and advantageous configurations of the first aspect of the invention are to be regarded as advantages and advantageous configurations of the second aspect of the invention and vice versa. The device is preferably a vehicle which can be driven by means of the reciprocating piston machine, in particular via its crankshaft. The vehicle is preferably a motor vehicle, in particular a motor vehicle and very particularly a passenger car. Furthermore, the device, in particular the vehicle, can be designed as a watercraft, in particular as a ship or boat, as a land vehicle, as a rail vehicle or as an airplane.

Overall, it can be seen that the second crankshaft is arranged between the first crankshaft and the connecting rod in relation to a power flow and is integrated in particular between the first crankshaft and the connecting rod. The first speed is also referred to as the crankshaft speed, it being preferably provided that when the first crankshaft rotates at the crankshaft speed, the second crankshaft rotates at a multiple, in particular an integer and/or odd number, of the crankshaft speed or half thereof. These rotations or rotational movements of the crankshafts relative to one another can be ensured in particular by the gears meshing with one another, in particular directly, with the first gear preferably being a so-called fixed gear. This means in particular that the first gear wheel is secured against rotation relative to the housing. In particular, the fixed wheel, which is formed separately from the housing, for example, is mounted on the housing and is therefore connected to the housing in a rotationally fixed manner.

Different connecting rod travel characteristics can then be selected by the so-called Fourier superimposition of the rotational frequencies of the two crankshafts. The respective connecting rod path characteristic is a characteristic of a path that is covered by the connecting rod during one complete revolution of the first crankshaft or during one working cycle of the reciprocating piston engine and thus during two complete revolutions of the first crankshaft. In particular, it is possible through the use of the crankshafts coupled to one another in an articulated manner that the maximum geometric compression taking place in the cylinder during the respective working cycle is not in the top dead center of the piston, but behind it.

The piston or its path determines the maximum geometric compression, which now no longer coincides with the top dead center of a crank of the first crankshaft, but the maximum geometric compression follows the reaching of the top dead center by the crank of the primary crankshaft, on its crank the second crankshaft is rotatably mounted about the second axis of rotation. This is advantageous in particular because the maximum geometric compression is a triggering event, also referred to as a trigger, for triggering or causing self-ignition of the mixture in the cylinder.

When using the two crankshafts, the first crankshaft can no longer necessarily be integrally manufactured by forging. If the reciprocating piston machine designed as an in-line engine, for example, has n cylinders, the first, primary crankshaft would then be formed from n+1 individual parts, for example, and n second, secondary crankshafts could then be provided. In this case, n designates an integer positive number. The first crankshaft is also referred to as the primary crankshaft or primary crankshaft, with the second crankshaft also being referred to as the secondary crankshaft or secondary crankshaft. The number of individual parts can be kept low if not just one connecting rod, but rather more than one connecting rod, is mounted on the crank pin of the secondary crankshaft. In particular, it is conceivable that all connecting rods of the reciprocating engine, also referred to as connecting rods, are rotatably or pivotably mounted on the same crank pin of the secondary crankshaft, in which case point-symmetrical kinematics would be advantageous, in which case a geometric arrangement of the cylinders could be similar to that of a radial engine. Partial stars would also be possible using more than one secondary crankshaft. For example, a 6-star could be divided axially into two half-stars, each with three cylinders, and the cranks of the primary crankshaft offset by 180°. The half-stars could be arranged in rows directly one behind the other as in an in-line engine (since the ignition offset between the half-stars is not caused by the geometric offset of the cylinders but by the phase offset caused by the differently arranged crank arms of the first primary crankshaft). This could improve the flat installation space characteristics of a radial engine in favor of a cuboid/compact design. In particular, the following can then apply: k=2n-2, where k designates an integer positive number whose reciprocal value, multiplied by 2, for example, corresponds or should correspond to the first radius to the second radius in order to be able to achieve a particularly high degree of efficiency. In particular, this means that after or during two, in particular complete, revolutions of the primary crankshaft, the secondary crankshaft has completed or is completing an integral number of rotations of its own and the entire arrangement is exactly at its starting point again (since a 4-stroke engine than the reciprocating engine is taken as a basis).

• 1 eine schematische Darstellung einer erfindungsgemäßen Hubkolbenmaschine;
• 2 ausschnittsweise eine schematische und geschnittene Seitenansicht einer ersten Ausführungsform der Hubkolbenmaschine, mit einer ersten, primären Kurbelwelle und einer zweiten, sekundären Kurbelwelle;
• 3 ein Diagramm zum Veranschaulichen eines Betriebs der Hubkolbenmaschine;
• 4 ein Diagramm zum Veranschaulichen einer Kinematik der Hubkolbenmaschine; und
• 5 ausschnittsweise eine schematische Seitenansicht einer zweiten Ausführungsform der Hubkolbenmaschine.

Further details of the invention result from the following description of preferred exemplary embodiments with the associated drawings. It shows:

• 1 a schematic representation of a reciprocating engine according to the invention;
• 2 a detail of a schematic and sectional side view of a first embodiment of the reciprocating engine, with a first, primary crankshaft and a second, secondary crankshaft;
• 3 a diagram for illustrating an operation of the reciprocating machine;
• 4 a diagram to illustrate a kinematics of the reciprocating engine; and
• 5 a detail of a schematic side view of a second embodiment of the reciprocating piston machine.

Elements that are the same or have the same function are provided with the same reference symbols in the figures.

1 shows a schematic representation of a reciprocating piston machine 1 for a device such as a vehicle, in particular a watercraft, an aircraft or a land vehicle such as a motor vehicle, in particular for a motor vehicle preferably designed as a passenger car. This means that the vehicle has the reciprocating engine 1 in its completely manufactured state and can be driven by means of the reciprocating engine 1 . The reciprocating engine 1 is designed as an internal combustion engine which can be operated in a fired mode. The internal combustion engine is also referred to as a motor, internal combustion engine or internal combustion engine. The reciprocating piston machine 1 has a housing 2, preferably designed as a crankcase, which has, in particular forms or delimits, a plurality of cylinders 3. In addition, the reciprocating engine 1 has a crankshaft 4 designed as an output shaft, which - as in conjunction with 2 can be seen - is rotatably mounted on the housing 2 about a first axis of rotation 5 relative to the housing 2 . For this purpose, the crankshaft 4 has at least one shaft journal 6, also referred to as a bearing journal. In particular, the crankshaft 4 can have a plurality of shaft journals 6, also referred to as bearing journals. The crankshaft 4 is rotatable about the axis of rotation 5 relative to the housing 2 via its shaft journal 6 the housing 2 stored. In particular, the shaft journals 6 are spaced apart from one another in the axial direction of the crankshaft 4 , the axial direction of the crankshaft 4 coinciding with the axis of rotation 5 .

As in 2 as can be seen from the example of one of the cylinders 3 , a respective piston 7 is accommodated in the respective cylinder 3 so that it can move in a translatory manner. In particular, is off 2 recognizable that the housing 2 has a cylinder wall 8, which limits the cylinder 3, in particular directly. Since the piston 7 is accommodated in the cylinder 3 in a translationally movable manner, the piston 7 can - as in 2 is illustrated by a double arrow 9, relative to the housing element 2 and thus move relative to the cylinder wall 8 translationally, in particular move back and forth. In addition, the reciprocating piston machine 1 has a connecting rod 10 for each piston 7, via which—as will be explained in more detail below—the respective piston 7 is coupled in an articulated manner to the first crankshaft 4.

Particularly good looking 2 it can be seen that the piston 7 and the cylinder 3 each partially delimit a respective combustion chamber 11 of the reciprocating piston engine 1 . Combustion chamber 11 is delimited at the top, for example, by a combustion chamber roof, in particular a cylinder head. The reciprocating piston engine 1 is designed as a four-stroke engine, so that a respective working cycle of the reciprocating piston engine 1 includes exactly two complete revolutions of the crankshaft 4 and thus exactly 720 degrees crank angle of the crankshaft 4 . Within the respective working cycle of the reciprocating piston engine 1, the combustion chamber 11 is supplied with an in particular liquid or gaseous fuel and with air. A fuel-air mixture, also referred to as air, is formed from the fuel and the air, which is ignited within the respective working cycle in particular by external ignition or by self-ignition in the combustion chamber 11 and is thereby burned in the combustion chamber 11 . Combustion of the mixture is also referred to as a combustion process or takes place as part of a combustion process. Exhaust gas from the reciprocating piston engine 1 results from the combustion of the mixture. The combustion of the mixture, in particular the resultant pressure build-up, drives the piston 7 , as a result of which the crankshaft 4 is driven via the connecting rod 10 . Driving the crankshaft 4 is to be understood in particular as meaning that the crankshaft 4 rotates about the axis of rotation 5 relative to the housing 2 in an in 3 illustrated by an arrow 12, first direction of rotation is rotated. Thus, if the reciprocating piston machine 1 is operated in its fired mode, then the fired mode includes several consecutive work cycles and thus several consecutive combustion processes. Thus, for example, the crankshaft 4 rotates in the fired operation at a first speed, also referred to as the crankshaft speed, about the axis of rotation 5 relative to the housing 2 in the first direction of rotation. For example, the crankshaft speed is 2 denoted by n _Mot . Thus, the crankshaft speed is the first speed of the primary or first crankshaft 4 rotating about the first axis of rotation 5 relative to the housing 2.

The respective work cycle of the reciprocating engine 1 includes exactly four cycles T1, T2, T3 and T4 ( 3 ). The cycles T1-4 follow each other directly or immediately after each other within the respective work cycle. The first stroke T1 is an intake stroke, also referred to as the intake stroke, during which the piston 7 moves from its top dead center (TDC), also referred to as the top gas exchange dead center (LWOT), to its bottom dead center (UT). In particular, the air is admitted or introduced or sucked into the combustion chamber 11 during the intake stroke. The first cycle T1 is immediately followed by the second cycle T2, which is a so-called compression cycle. During the compression stroke, the piston 7 moves from its bottom dead center to its top dead center (TDC), which is also referred to as the ignition top dead center (ZOT), as a result of which the aforementioned mixture is compressed. After and/or during the compression, the mixture is ignited, whereby this ignition can be an external ignition or a self-ignition and in 3 illustrated at 13 . The third stroke T3, which immediately follows the second stroke T2, is a so-called power stroke, during which the piston 7 moves from its top dead center or from its top ignition dead center to its bottom dead center. Combustion of the mixture takes place particularly during the power stroke. The fourth stroke T4, which immediately follows the third stroke T3, is an exhaust stroke, during which the piston 7 moves from its bottom dead center to its top dead center. The combustion of the mixture results in exhaust gas, which is expelled from the cylinder 3 or from the combustion chamber 11 by means of the piston 7 during the exhaust stroke. In 3 D1, D3, D5, D7 and D9 are the respective rotational positions of the crankshaft 4, also referred to as crank angles or degree crank angles, with the crankshaft 4 coming into the respective rotational positions or assuming the respective rotational positions during the respective working cycle. Through points is in 3 illustrates that between the rotational positions D1 and D3 or D3 and D5 or D5 and D7 or D7 and D9 there can be several further rotational positions of the crankshaft 4.

By driving the piston 7 and driving the crankshaft 4 resulting therefrom, the crankshaft 4 can rotate in 2 provide torque T shown schematically to drive the vehicle. As a result, the vehicle can be driven by an internal combustion engine. the end 1 it can be seen that the crankshaft 4 can be connected by means of a clutch Ko to another shaft 33 in a torque-transmitting manner, in particular non-rotatably. The other shaft 33 is, for example, a transmission input shaft of a transmission of the vehicle. Thus, for example, the torque T or a further torque resulting from the torque T can be transmitted via the clutch Ko to the further shaft 33, as a result of which the further shaft 33 and thus, for example, the transmission can be driven. In addition, 1 an intake tract 14 of the reciprocating piston engine 1, also referred to as the intake tract, can be seen. The air can flow through the intake tract 14 , which air is guided to and in particular into the combustion chambers 11 by means of the intake tract 14 . In addition, 1 an exhaust tract 15 of the reciprocating engine 1 shown particularly schematically. The aforementioned exhaust gas can flow out of the respective combustion chamber 11 and into the exhaust gas duct 15 and flow through the exhaust gas tract 15 . An exhaust gas turbocharger 16 can be assigned to the reciprocating piston engine 1 . The exhaust gas turbocharger 16, the turbine wheel 17, the compressor wheel 18 and the shaft 19 are purely exemplary or optional and can be omitted. The exhaust gas turbocharger 16 has a turbine wheel 17 which is arranged in the exhaust gas tract 15 and can be driven by the exhaust gas and a compressor wheel 18 which is arranged in the intake tract 14 and can be driven by the turbine wheel 17 and which can be driven by the turbine wheel 17 via a shaft 19 of the exhaust gas turbocharger 16. By driving the compressor wheel 18 , the air flowing through the intake section 14 is compressed by means of the compressor wheel 18 . Thus, the reciprocating engine 1 is preferably designed as a turbo engine.

In order to be able to achieve a particularly high degree of efficiency of the reciprocating-piston machine 1, the reciprocating-piston machine 1 has at least or exactly one second crankshaft 20, in particular for each connecting rod and/or for each piston and/or for each cylinder, which is spaced apart from the first axis of rotation 5 , second axis of rotation 21 is rotatably mounted on the first crankshaft 4 relative to the first crankshaft 4 . The first crankshaft 4 is also referred to as the primary crankshaft or primary crankshaft, with the second crankshaft 20 also being referred to as the secondary crankshaft or secondary crankshaft. In addition, the second crankshaft 20 has a crank pin 22 with which the piston 7 is coupled in an articulated manner via the connecting rod 10 . For example, the connecting rod 10 is coupled to the piston 7 in an articulated manner such that the connecting rod 10 is coupled to the piston 7 such that it can pivot about a first pivot axis S1 relative to the piston 7 . This means that the piston 7 and the connecting rod 10 can pivot relative to one another about the first pivot axis S1, the pivot axis S1 being spaced apart from the axes of rotation 5 and 21 and preferably running parallel to the axes of rotation 5 and 21. The axes of rotation 5 and 21 are also spaced apart from one another, with the axes of rotation 5 and 21 running parallel to one another. On the other hand, the connecting rod 10 is coupled to the crank pin 22 in an articulated manner in such a way that the connecting rod 10 is coupled or connected to the crank pin 22 such that it can pivot about a second pivot axis S2 relative to the crank pin 22 . This means that the connecting rod 10 and the crank pin 22 can rotate or pivot relative to one another about the pivot axis S2. The pivot axis S2 is at a distance from the pivot axis S1 and from the axes of rotation 5 and 21 , it being preferably provided that the pivot axis S2 runs parallel to the pivot axis S1 and parallel to the axes of rotation 5 and 21 . It can be seen that the first crankshaft 4 can have crank rods 23, which in 2 shown embodiment are designed as crank webs.

2 shows a first embodiment of the reciprocating piston machine 1. The connecting rods 23, which are designed as crank webs in the present case, are spaced apart from one another in the axial direction of the crankshaft 4 and extend obliquely or, in the present case, perpendicularly from the shaft journal 6. The secondary crankshaft is rotatably connected to the connecting rods 23 about the axis of rotation 21 relative to the connecting rods 23 or is supported on the connecting rods 23 . The secondary crankshaft 20 in turn has, for example, at least one shaft journal 24, also referred to as a bearing journal. In particular, the secondary crankshaft can have at least or precisely one additional or second shaft journal 24 for each connecting rod 23, also referred to as an additional or second bearing journal. The secondary crankshaft is mounted on the primary crankshaft, in particular on the connecting rods 23 , such that it can rotate about the axis of rotation 21 relative to the primary crankshaft via the shaft journals 24 . For example, the shaft journals 24 are spaced apart from one another in the axial direction of the crankshaft 20 whose axial direction runs parallel to the axial direction of the crankshaft 4 . Furthermore, the secondary crankshaft can have additional or second connecting rods 25 , which preferably extend away from the shaft journal 24 at an angle or perpendicularly to the axis of rotation 21 . The crank pin 22 is connected to the crank rods 25 so that the crank pin 22 is connected to the shaft journal 24 via the crank rods 25 . As a result, the crank pin 22 and thus the pivot axis S2 are separated from the shaft journal 24 and spaced from the axis of rotation 21, the axis of rotation 21 being defined by the shaft journals 24 and by the connecting rods 23, for example. Furthermore, it is conceivable that the pivot axis S2 is defined by the crank pin 22 .

Overall, it can be seen that the reciprocating piston engine 1 has a crankshaft device 26 which includes the crankshafts 24 . Viewed globally, the crankshaft device 26 can have a first crank 27 which comprises the connecting rods 23 and the crankshaft 20 . In comparison to conventional crankshafts, the crankshaft 4 does not therefore have a crank pin that connects the connecting rods 23 to one another and cannot rotate relative to the connecting rods 23, but instead has a crank pin that connects the connecting rods 23 to one another and cannot rotate relative to the connecting rods 23 the crankshaft 20, which is mounted on the connecting rods 23 and thus on the crankshaft 4 so that it can rotate about the axis of rotation 21 relative to the connecting rods. The crankshaft 20 in turn comprises the shaft journals 20, which are preferably designed as further crank webs, further connecting rods 25 and the crank pin 22 which, for example, connects the connecting rods 25 to one another and cannot be rotated relative to the connecting rods 25. On the other hand, the connecting rod 10 is rotatably mounted on the crank pin 22 so that the connecting rod 10 is coupled in an articulated manner to the crankshaft 4 via the crankshaft 20 or via the crank 27 .

In 2 a first radius is denoted by R _KW , while a second radius is denoted by R _PL . A third radius is denoted by R _SKW . A fourth radius is labeled RFR. For example, h _PI designates a height of the connecting rod 10, the height of the connecting rod 10 being a distance between the pivot axes S1 and S2 running perpendicular to the pivot axes S1 and S2. The pivot axis S1 coincides, for example, with the longitudinal axis, in particular with the longitudinal center axis, of a piston pin and/or a first seat of the connecting rod 10 and/or at least one second seat of the piston 7 . The piston 7 is coupled in an articulated manner to the connecting rod 10 via the piston pin. In particular, it is conceivable that at least a first length of the piston pin is arranged in the seat of the connecting rod 10 and at least a second length of the piston pin is arranged in the seat of the piston 7, whereby the piston 7 is arranged over the piston pin, whereby the piston 7 is arranged over the piston pin is articulated to the connecting rod 10 coupled.

It is also conceivable that the pivot axis S2 coincides with a longitudinal axis, in particular with a longitudinal central axis, of the crank pin 22 and/or a further receptacle of the connecting rod 10, in the further receptacle of which at least a longitudinal region of the crank pin 22 is arranged, as a result of which the connecting rod 10 is articulated is coupled to the crank pin 22 or is rotatably or pivotably mounted on the crank pin 22 . The first radius is a first distance between the axes of rotation 5 and 21 perpendicular to the axes of rotation 5 and 21. The second radius is a second distance between the axis of rotation 21 and the pivot axis S2 perpendicular to the axis of rotation 21 and perpendicular to the pivot axis S2.

At this point it should be mentioned that not only one connecting rod 10 can be attached to the crankpin 22 of the second, secondary crankshaft 20, but several (possibly with different bank angles). It is also conceivable that not only one crank of a secondary crankshaft 20 or not only one secondary crankshaft 20 but rather several secondary crankshafts 20 can hang or be mounted on the connecting rods 23 of the first, primary crankshaft 3 .

In the first embodiment, the second crankshaft 20 is positively coupled to the housing 2 in such a way that a rotation of the first crankshaft 5 about the axis of rotation 5 relative to the housing 2 in the first direction of rotation results in a rotation about the second axis of rotation 21 relative to the housing 2 and relative to the first crankshaft 5 in a second direction of rotation opposite to the first direction of rotation of the second crankshaft 20 results, the second direction of rotation in 3 is illustrated by an arrow 28. In the second embodiment, the secondary crankshaft is positively coupled to the housing 2 in the manner described above in such a way that a first gear wheel 29, also referred to as a fixed wheel and in the present case designed as a ring gear, is provided on the housing 2 and a second gear wheel 30 on the crankshaft 20. gears 29 and 30 meshing directly with each other, i.e. directly meshing with each other. The ring gear could also be viewed as rotating and/or adjustable by an angular range about the axis of rotation 5 ( 2 ), i.e. with a variable speed. A valve train would then have to be controlled mechatronically or kinematically by the connecting rod stroke, for example, because kinematic control purely via the first, primary crankshaft 4 is no longer sufficient or would no longer match the cycle of the cylinder stroke (due to the new degree of freedom of the ring gear speed). For example, if the ring gear does not rotate continuously, but only by one Angle delta (discrete or continuous) is adjusted, so different connecting rod travel characteristics (discrete/continuous) can be adjusted. For continued expedient or favorable engine operation, the ignition angle and valve train could then be adjusted or designed to be adequately adjustable.

While the gear 30 is connected to the crankshaft 20 in a rotationally fixed manner, the gear 29 is connected to the housing 2 in a rotationally fixed manner. As a result, the crankshaft 20 and the housing 2 are coupled to one another in such a way that when the first crankshaft 4 rotates at the crankshaft speed n _Mot (first speed) about the first axis of rotation 5 relative to the housing 2, the second crankshaft 20 rotates at a is rotated about the axis of rotation 21 relative to the crankshaft 4 and relative to the housing 2 at a speed different from the first speed, for example greater than the first speed. The second speed does not necessarily have to be greater than the first speed. This depends on the ratio of the radii (ie in the case of the second secondary crankshaft 20: the ratio of the translatory bypassing of the primary, first crankshaft 4 around the axis of rotation 5 versus its own rotation/rotational speed around the axis of rotation 21). The rotational speed of the secondary crankshaft 20 relative to or about the axis of rotation 21 is generally a different rotational speed than that of the secondary crankshaft 20 relative to or about the axis of rotation 5. Analogous to how the earth orbited the sun with a circular frequency of 1/year they also have their own angular frequency by self-rotation of 1/day. If the self-rotation were =0, then a day would be stretched over the course of a whole year. Example: in 3 the circumference of the secondary crankshaft 20 rolls over the circumference of the ring gear three times per revolution in the ring gear (crank pin is every 120° = 3x inside and 3x outside). However, the secondary crankshaft 20 rotates only twice relative to or about the axis of rotation 5 of the primary crankshaft 4 (the crank pin is every 180° relative to the secondary crankshaft 20 or twice per revolution in the ring gear at the bottom and twice at the top).

For example, the second speed of the second, secondary crankshaft 20 rotating about the axis of rotation 21 relative to the first, primary crankshaft 4 is an integer multiple of the first speed. Preferably, the second speed is exactly four times the first speed. The third radius is, for example, a third distance running perpendicular to the axis of rotation 21 and perpendicular to the pivot axis S2 between the axis of rotation 21 and the gear wheel 29, which is preferably designed as a ring gear. In other words, it is preferably provided that the gear wheels 29 and 30, in particular their Gearing and in particular their base circles are matched to one another in such a way that the second speed resulting from the first speed is an integer multiple of the first speed and preferably exactly four times the first speed. At the in 2 , 3 and 4 Thus, as illustrated in the first embodiment, R _SKW = R _KW /4 is preferably provided.

Preferably one in 2 supply device 31, shown particularly schematically, by means of which the gear wheels 29 and 30, in particular their gear teeth which are in direct engagement with one another, are supplied with a lubricating and/or coolant for lubricating and/or cooling the gear wheels 29 and 30, in particular the gear teeth of the gear wheels 29 and 30, are suppliable. The lubricating and/or cooling agent is preferably a liquid, in particular an oil also referred to as lubricating oil.

Specifically illustrated 3 a piston kinematics of a crank drive comprising the crankshaft device 26 and the connecting rod 10 and the piston 7 . A dashed arrow 32 illustrates a piston path which is covered by the piston 7 within the respective working cycle. In particular, the arrow 32 illustrates the connecting rod 10 and its position, with the arrow 32 pointing in the direction of the piston 7 . In relation to a coordinate system, which has an x-axis labeled x and a y-axis running perpendicular thereto, labeled y, the piston moves, for example, along the y-axis, with a lever arm being formed along the x-axis, which runs perpendicularly to the axis of rotation 5, the torque T resulting from a force resulting from the combustion of the mixture and acting on the piston, in particular along the y-axis, multiplied by the lever arm. This coordinate system is intended to be fixed to the housing. The y-axis shows the piston travel or the direction of the cylinder bore. The x-axis conditionally shows the resulting lever arm of the primary crankshaft or the x-position of the axis of rotation 21 of the secondary crankshaft, ie its projected distance from the axis of rotation (z-direction) of the primary crankshaft. Also illustrated 4 piston kinematics and the crank kinematics of the crank mechanism, φ _KW denoting the respective rotational position of the primary crankshaft and φ _{SKW denoting} a respective rotational position of the second, secondary crankshaft 20 in relation to the first, primary crankshaft. With regard to a respective arc length of the respective toothing, the following preferably applies: φ _KW * R _FR =! φ _SKW * R _SKW It follows: φ _SKW = φ _KW * R _FR / R _SKW .

In addition, an integer periodic perimeter ratio is preferably provided: $$\text{k}*\mathrm{\pi }*{\text{R}}_{\text{SKW}}=\text{!}2\mathrm{\pi }*{\text{R}}_{\text{week}}.\text{It follows from this: k}=2{\text{*R}}_{\text{week}}{\text{/R}}_{\text{SKW}}\text{!}=\mathrm{1,2,3}...$$

Therefore: The traversed arc of R _SKW must be an integer multiple of the double circle of RFR. So k*2*pi*R _SKW = 2*(2*pi*R _FR ) = 2*2*pi*(R _KW + R _SKW ).

• R_SKW = 2*R_KW/(k-2) mit k = 3,4,5... (beginnt also nicht mit 1 weil dann die Werte negativ wären für 1 und 2 - aber die Ergebnisreihe für R_SKW sind sonst dieselben, nur um zwei ganze Zahlen für k verschoben. Daraus folgt R_SKW = 2 * R_KW / k.
• k=1: 3er-Stern, 2-taktig
• k=2: Kreis/Ellipse, 1-taktig
• k=3: 5er-Stern, 2-taktig
• k=4: 3er-Stern, 1-taktig
• k=5: 7er-Stern, 1-taktig
• k=6: 4er-Stern, 1-taktig
• k=7: 9er-Stern, 2-taktig
• k=8: 5er-Stern, 1-taktig
• k=9: 11er-Stern, 1-taktig
• k=10: 6er-Stern, 1-taktig
• k=11: 13er-Stern, 2-taktig
• k=12: 7er-Stern, 1-taktig
• k=13: 15er-Stern, 2-taktig
• k=14: 8er-Stern, 1-taktig
• usw.

mit „taktig“ ist hier gemeint ist, wie viele Umdrehungen der primären Kurbelwelle es (mindestens) braucht, damit der Kolben seinen (maximalen) oberen und (minimalen) unteren Totpunkt mindestens oder genau einmal durchfährt. Vorzugsweise ist folgende kinematische Zwangsbedingung vorgesehen: RFR = R_KW + R_SKW. Der maximale, von dem Kolben 7 während des Arbeitsspiels zurücklegbare oder zurückgelegte Weg wird auch als Kolbenhub y_K bezeichnet und ergibt sich zu: $${\text{y}}_{\text{K}}={\text{y}}_{\text{PI}}+\text{sqrt}\left({\text{<figure-callout id="2" label="h PI" filenames="DE102020125196A1\_0003.png,DE102020125196A1\_0004.png" state="{{state}}">h</figure-callout>}}_{\text{PI}}{}^2-{\text{x}}_{\text{PI}}{}^2\right)$$

Insbesondere kann k 4, 6, 8 oder eine andere, positive ganze Zahl betragen.This results in:

• R _SKW = 2*R _KW /(k-2) with k = 3,4,5... (does not start with 1 because then the values would be negative for 1 and 2 - but the series of results for R _SKW are otherwise the same , only shifted by two integers for k. It follows that R _SKW = 2 * R _KW / k.
• k=1: 3-star, 2-bar
• k=2: circle/ellipse, 1 bar
• k=3: 5-star, 2-bar
• k=4: 3-star, 1-bar
• k=5: 7 star, 1 bar
• k=6: 4 star, 1 bar
• k=7: 9-star, 2-bar
• k=8: 5 star, 1 bar
• k=9: 11 star, 1 bar
• k=10: 6 star, 1 bar
• k=11: 13-star, 2-bar
• k=12: 7 star, 1 bar
• k=13: 15 star, 2 bars
• k=14: 8 star, 1 bar
• etc.

"clocked" here means how many revolutions of the primary crankshaft it takes (at least) for the piston to pass through its (maximum) top and (minimum) bottom dead center at least or exactly once. The following kinematic constraint is preferably provided: RFR=R _KW +R _SKW . The maximum distance covered or covered by the piston 7 during the working cycle is also referred to as the piston stroke y _K and results in: $${\text{y}}_{\text{K}}={\text{y}}_{\text{PI}}+\text{square}\left({\text{<figure-callout id="2" label="H PI" filenames="DE102020125196A1\_0003.png,DE102020125196A1\_0004.png" state="{{state}}">H</figure-callout>}}_{\text{PI}}{}^2-{\text{x}}_{\text{PI}}{}^2\right)$$

In particular, k can be 4, 6, 8 or another positive integer.

In particular, the use of the crankshafts 24 makes it possible for the piston 7 to remain in its top dead center longer than in conventional reciprocating piston machines, so that, for example, a piston movement curve illustrating the movement of the piston 7 in the cylinder 3 over a degree crank angle, which takes place during the respective working cycle, is shown Has plateau, which illustrates the top dead center of the piston 7 or a period of time during which the piston 7 remains in its top dead center, but in particular while the crankshaft 4 rotates. The plateau can be practically level or have a positive or negative slope. The plateau is the piston stroke as a function of time or the crankshaft angle of the primary, first crankshaft 4.

The shape of this plateau at top dead center can be set or changed via R _PI / R _SKW . For example, a setting or change is only possible within the framework of the kinematic constraints. For example, shoulders of the plateau can be designed horizontally, sloping or rising. Alternatively or additionally, the mixture can be ignited automatically by blowing in air, for example in such a way that fuel is first injected, in particular directly injected, into combustion chamber 11 within the respective working cycle and during compression and/or after compression, and then air is injected into combustion chamber 11 , In particular directly, is blown.

Said plateau is also referred to as a compaction plateau, which can be adjusted as required. In particular, a combination with air injection is conceivable, as a result of which degrees of freedom with regard to the controllability or regulation of the compression can be created. In particular, a variable energy content per piston stroke can be created with a constant combustion air ratio λ, in particular without changing the valve control. Compared to conventional solutions, the intermediate pressure can be increased, which increases the exhaust gas temperature. As a result, for example, an advantageous response behavior of an exhaust gas aftertreatment device arranged in the exhaust gas tract 15 can be presented.

In other words, self-ignition operation of the reciprocating piston machine 1 can be implemented, with the mixture being ignited, in particular exclusively, by self-ignition in the self-ignition operation. The self-ignition operation is preferably checked with regard to alternative and/or gaseous fuels, since their self-ignition temperature is very high compared to diesel fuels and gasoline or Otto fuels. In particular, the use of synthetic fuels such as methane and methanol is also conceivable. There is therefore a very high potential here for realizing a particularly high, maximum pressure in the combustion chamber 11 with a low risk of knocking, as a result of which a particularly high level of efficiency can be achieved. In addition, an advantageous mixture formation can be realized, and high particle emissions, especially when using gas or liquid gas as fuel, can be kept low, since, for example, evaporation of initially liquid droplets and thus a transition of such droplets from the liquid to the gaseous state can be omitted . In addition, no carbon nests or particles are formed, or they are smaller than in conventional solutions, which possibly burn off by themselves due to the increased process temperature with sufficient turbulence in the cylinder 3 or in the exhaust tract 15, also referred to as the exhaust system or exhaust line. When burning natural gas and/or biogas, the reciprocating engine 1, also known as a piston engine, could be used as a stationary power generator and thus compete with gas turbine power plants.

Finally shows 5 a second embodiment of the reciprocating engine 1. As from 5 As can be seen, it is conceivable that on the respective crank pin 22 of the secondary crankshaft, several connecting rods 10 and 10′, which are designed separately from one another, can be mounted in a rotatable or pivotable manner at the same time. The following and previous statements on the connecting rod 10 can also be applied to the connecting rod 10' without further ado, and vice versa. The second embodiment is, so to speak, a boxer design (bench angle 180°) that can easily be displayed on a 2D image. Also possible and probably more sensible are bank angles that result from the speed ratio: 120°, 90°, 72°... (i.e. 360°/k). By installing several connecting rods per secondary crankshaft 20, crankpins of the prim KW can be saved (in the extreme case you get a radial engine: only one KW crankpin, on which all cylinders are arranged in turn and all connecting rods drive the same crankpin. The other extreme is an in-line engine with bench angle 0°).

In the second embodiment, exactly two connecting rods 10 and 10′ are mounted on the crank pin 22 so that they can be rotated or pivoted at the same time and are thus coupled in an articulated manner to the crank pin. The respective connecting rods mounted simultaneously or jointly pivotably or rotatably on the crank pin 22 or the associated pistons and their piston paths can be offset from one another by 90 degrees or by 180 degrees, for example, along the first direction of rotation or along the second direction of rotation. As a result, the constructive outlay for balancing masses can be kept particularly low, since two pistons 7 always execute point-symmetrical movements with respect to the axis of rotation 5, which is also referred to as the crankshaft axis. Opposite (in the narrower sense) can be provided in the special case that the angular offset of the primary crank pins is 180°.

For example, the respective connecting rods that are simultaneously rotatably or pivotably mounted on the respective crank pin 22 can be star-shaped, which has, for example, exactly three rays and thus exactly three connecting rods, exactly four rays and therefore exactly four connecting rods or exactly six rays and thus exactly six connecting rods . The reciprocal of an integer multiple is also conceivable. Example: 6 cylinders can be distributed a) all 6 in turn on 1 KW crankpin or b) on 2 KW crankpins with a crankpin offset of 180° and bank angle 60° or c) on 3 KW crankpins with a crankpin offset of 120° and bank angle 60° ° or d) as an in-line engine: on 6 KW crankpins with bank angle 0°

In other words, it is conceivable for three, four, five, six, seven, eight, nine, ten, eleven, twelve or more to be mounted separately or separately on the respective crank pin 22 at the same time trained connecting rod can be pivoted or rotatably mounted. This also applies to an internal combustion engine based on the current state of the art, but the point-symmetrical character of the kinematics means that it also applies to the reciprocating piston engine 1 with the two crankshafts 4 and 20 . An innovation, however, is the additional possibility that the connecting rod travel characteristic is not completely covered after one revolution of the primary crankshaft (primary crankshaft), but only after two revolutions (odd-numbered stars with crank pin paths crossing each other from the 5th star: 3rd star, 5th , 7s, 9s...). As a result, different ratios of intake path = compression path to power cycle path = exhaust path can be implemented. In other words, the geometric suction path and the working path can be different. The same applies to the geometric ejection path and the compression path. With a corresponding angular offset between the primary and secondary crank pins, all four paths are even different from one another. The effect of variable compression is possible in a prior art conventional internal combustion engine via variable control of the valve train. However, this invention is based on this effect kinematically, so that a good degree of efficiency is achieved due to the Intake greater expansion path can be achieved without a variable valve train. With an appropriate design, the (maximum) expansion path is still larger, even if the maximum possible intake path is fully utilized. This also brings an efficiency advantage because the expansion path is longer than the compression path. This additional usable expansion energy also reduces the mean pressure (while the maximum pressure remains the same) and thus the mean temperature in the cylinder and thus eases the challenge for the material technology to meet the increased temperatures in the cylinder and exhaust system compared to the state of the art.

When using a star shape with exactly three rays, there is exactly one secondary crankshaft with exactly one crank pin 22 and thus a fully occupied star for a three-cylinder engine for example, 180 degrees offset from each other and in a twelve-cylinder engine, for example, four crank pins 22 are used, in which case the star shapes are offset, for example, 90 degrees from each other. For a star shape with four beams or four connecting rods, a four-cylinder engine results in either a fully occupied crank pin 22 or two crank pins 22 with an offset of 180 degrees and a 90-degree V arrangement can be provided, with one Eight-cylinder engine, two fully occupied star shapes, each with four beams or four crank pins 22, each with two connecting rods, result in particular in a V arrangement, and with a 12-cylinder engine, three fully occupied stars result, each offset by 120 degrees from one another . For a star shape with exactly six rays, for example, in a three-cylinder engine, only half of one crank pin 22 is occupied; for a four-cylinder engine, for example, there are two crank pins 22 each with 2/6 occupied 60 degree angles at 180 degrees offset, for a six-cylinder engine there is a fully occupied star or there are two half-occupied stars in a three-finger arrangement offset by 180 degrees, and for a twelve-cylinder engine there are two fully occupied stars with 180 degrees offset or four half-occupied stars each 90 degrees offset from each other and thus a three-finger arrangement.

It is also conceivable that the crankshafts rotate in the same, in particular the first, direction of rotation. The following design modifications would then be provided for this: In a first modification, the secondary crankshaft 20 no longer rolls “outside” as seen from the axis of rotation 5 (cf. 3 ) on RFR, but "inside" (like the pulley of a gondola on a rope). So no longer RFR = R _KW + R _SKW but RFR = R _KW - R _SWK . Thus, for example, the ring gear is changed: from a ring gear with internal teeth, it becomes a spur gear with external teeth.

So that the spur gear mentioned above, into which the ring gear was converted, does not collide with the connecting rods 23, one of the two connecting rods 23 (i.e. in 2 for example, everything to the left of the connecting rod 10 would be omitted and the gear 29 would be a spur gear).

In a second modification, a spur gear is installed for the rolling movement between the secondary crankshaft 20 and the ring gear (gear 29), which then reverses the direction of rotation of the secondary crankshaft 20, so that the crankshafts 4 and 20 rotate in the same, in particular the first, direction of rotation . Preferably R _KW is twice as large as R _SKW . For each complete revolution of the primary crankshaft 4, the piston 7 always travels the same path (piston path versus crankshaft angle is identical for each crankshaft revolution). It is also conceivable that when the first crankshaft 4 rotates at the first speed about the first axis of rotation 5, the second crankshaft 20 rotates about the second axis of rotation 21 at a second speed, which is an integer multiple of the half of the first speed. So, for example, R _KW is 3/2 times or 1/2 times as large as R _SKW . Then the secondary crankshaft 20 requires not one, but two complete revolutions of the first crankshaft 4 for a closed travel or for a complete revolution (i.e. progression of piston travel over KW angle). The piston 7 travels two different paths alternately for each KW revolution (rotation of the primary crankshaft 4), at the end of which the other path then connects again (similar to a Möbius strip). These paths (of the connecting rod foot point or crank pin) then "cross" (plotted in the xy traverse path level), since the piston 7 does not move from one "corner" (crank pin has maximum distance to the KW axis) of the path to the next, but always directly to the next but one (thus the figure always has an odd number of corners). By means of an angular offset or misalignment (of, for example, 90°) of the secondary crankshaft 20 in relation to the primary crankshaft 4, the traversing path figure can be rotated as desired in the xy plane. So you can (within certain limits) - in addition to shifting the max. compression behind the top dead center - also make the compression and expansion paths of different lengths, e.g. make the expansion path larger than the path for compression, which also brings an efficiency advantage. This entire paragraph applies in general and not only to the above 1st and 2nd modification or embodiment.

Reference List

1

reciprocating machine

2

housing

3

cylinder

4

first crankshaft

5

axis of rotation

6

shaft journal

7

Pistons

8th

cylinder wall

9

double arrow

10, 10'

connecting rod

11

combustion chamber

12

arrow

13

ignition

14

admission tract

15

exhaust tract

16

exhaust gas turbocharger

17

turbine wheel

18

compressor wheel

19

wave

20

second crankshaft

21

axis of rotation

22

crank pin

23

connecting rod

24

shaft journal

25

connecting rod

26

crankshaft device

27

crank

28

arrow

29

gear

30

gear

31

utility facility

32

arrow

33

wave

D1-9

rotary position

hPI

height

nMot

crankshaft speed

knockout

coupling

RKW

radius

RPL

radius

RSKW

radius

S1, S2

pivot axis

T

torque

T1-T4

tact

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• EP 2633166 B1 [0003]

Claims (11)

Reciprocating piston machine (1), with a housing (2), with a crankshaft (4) which is mounted on the housing (2) so that it can rotate about an axis of rotation (5) relative to the housing (2), with at least one cylinder (3) , And with at least one translationally movable piston (7) accommodated in the cylinder (3), which is coupled in an articulated manner to the crankshaft (4) via at least one connecting rod (10), characterized by at least one second crankshaft (20) which rotates about a spaced apart from the axis of rotation (5) and running parallel to the axis of rotation (5), the second axis of rotation (21) is rotatably mounted on the first crankshaft (4) relative to the first crankshaft (4) and has at least one crank pin (22), with which the piston (7) is articulated via the connecting rod (10). Reciprocating machine (1) after claim 1 , characterized in that the second crankshaft (20) is coupled to the housing (2) in such a way that from a rotation about the first axis of rotation (5) relative to the housing (2) taking place rotation of the first crankshaft (4) about the second Axis of rotation (21) relative to the housing (2) and relative to the first crankshaft (4) resulting rotation of the second crankshaft (20). Reciprocating machine (1) after claim 2 , characterized in that the second crankshaft (20) is coupled to the housing (2) in such a way that the first crankshaft rotates about the first axis of rotation (5) relative to the housing (2) in a first direction of rotation (12). (4) a rotation of the second crankshaft (20) about the second axis of rotation (21) relative to the housing (2) and relative to the first crankshaft (4) in a second direction of rotation (28) opposite to the first direction of rotation (12) results. Reciprocating machine (1) after claim 2 or 3 , characterized in that the second crankshaft (20) is so coupled to the housing (2) that the second crankshaft (20) when the first crankshaft (4) at a first speed (n _Mot ) to the first Axis of rotation (5) rotates, the second crankshaft (20) rotates about the second axis of rotation (21) at a second speed, which is an integer multiple of half the first speed (n _Mot ). Reciprocating machine (1) after claim 4 , characterized in that the second speed is at least or exactly four times the first speed (n _Mot ). Reciprocating machine (1) according to one of claims 2 until 5 , characterized by : - at least one first toothed wheel (29) provided on the housing (2); and - on the second crankshaft (20) provided, second gear (30) which is directly engaged with the first gear (29), whereby the second crankshaft (20) is coupled to the housing (2). Reciprocating machine (1) after claim 6 , characterized in that the first gear (29) rotatably connected to the housing (2), in particular integrally formed with the housing (2), is. Reciprocating machine (1) after claim 6 , characterized in that the first gear (29) is rotatable relative to the housing (2). Reciprocating machine (1) according to one of Claims 6 until 8th . characterized in that the first gear (29) is designed as a ring gear. Reciprocating machine (1) according to one of Claims 6 until 9 , characterized in that the second gear (30) rotatably connected to the second crankshaft (20), in particular integrally formed with the second crankshaft (20), is. Device with at least one reciprocating piston machine (1) according to one of the preceding claims.

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