DE102008046426A1 - Compression ratio changing arrangement for combustion engine i.e. Otto engine, has spring unit partially absorbing gas and mass forces acting at positioning device during operation of engine in relation to actuating device - Google Patents

Abstract

The arrangement (10) has a positioning device (12) changing position of a piston (16) relative to a cylinder (18) of a combustion engine for adjusting compression ratio. An actuating device (20) i.e. servo-motor, is in effective connection with the device (12) for actuating the device (12). A spring unit (22) e.g. spiral spring, partially absorbs gas and mass forces acting at the device (12) during operation of engine in relation to actuating device. The unit is arranged and dimensioned such that retaining forces and/or moments acting at the actuation device act only in a certain direction.

Description

Field of the invention

The The invention relates to an arrangement according to the preamble of claim 1 for varying the compression ratio in an internal combustion engine. Furthermore, the invention relates to a Internal combustion engine according to claim 18 with a such arrangement for varying the compression ratio.

State of the art

Background of the invention

Around the most energy-efficient operation of an internal combustion engine, In particular, to achieve an Otto engine, it is known that Compression ratio to the operating condition of the engine adapt. So can an Otto engine due to the auto-ignition the fuel in full load operation only with a compression ratio be operated by ε = 9, while in partial load operation to reduce the fuel consumption, a higher compression ratio for example, ε = 14 would be desirable.

Out the state of the art are very different solutions known, the compression ratio during the Adjust the operation of the internal combustion engine. in principle For this purpose, the relative position of the piston to the cylinders of the internal combustion engine changed, in this way that of the respective piston and to change the volume limited to the associated cylinder.

To the Changing the relative position of the pistons to the cylinders serves an adjusting device, with the example, the crankshaft can be displaced relative to the cylinders. Also, solutions are out known in the prior art, in which the cylinder relative to Crankshaft be displaced, for example by pivoting the entire engine block or by adjusting the cylinder head of the engine.

From the DE 297 19 343 U1 An arrangement for varying the compression ratio is known in which an eccentric bearing arrangement for the crankshaft is provided as adjusting device, with which by pivoting the bearing assembly about the eccentric axis, the crankshaft is displaced relative to the cylinders. Corresponding solutions with eccentric bearing arrangement for the crankshaft are from the DE 30 04 402 A1 , of the DE 36 01 528 A1 or the DE 36 44 721 A1 known.

To the Adjusting the adjusting device is an actuating device, acting directly on the actuator, for example an electric servomotor, an electric linear actuator or else a hydraulically or pneumatically controlled linear actuator. The Actuator is in turn in a known manner controlled by the engine control of the internal combustion engine and actuates the Actuator depending on the current motor parameters.

At the Operation of the internal combustion engine produces both gas and mass forces, that of the cylinders, the cylinder head or the crankshaft bearing must be included. Act in a similar way these forces also directly on the adjusting device, which changes the relative position of the pistons to the cylinders becomes.

In Dependence on the articulation of the actuator to the actuator also arise on the actuator forces or moments acting in changing directions, which to corresponding holding moments or holding forces to lead.

For a high degree of dynamics and guarantee of adjustability the arrangement at low operating temperatures (high friction torque on the crankshaft) is basically a coupling with high efficiency in the efficiency chain at the same time as possible low acting on the actuator mass moment of inertia necessary. Self-locking gears generally have a low Efficiency on and allow fundamental no automatic adjustment when reversing the power flow direction. However, this is to achieve a fail-safe location for necessary in case of failure.

Especially in a non-self-locking execution of the transmission kinematics A reversal of the torque direction leads to a loss the frictional connection in the transmission kinematics, for example in the toothing or between the spindle shaft, ball and spindle. This creates mechanical system changes. This investment change take place with the frequency of excitation and lead to a strong noise. Furthermore, reduce the Plant change the life of the mechanism crucial.

For the most efficient adjustment of the wave to reach good Verstelldynamik is the transmission kinematics for However, achieving high efficiency usually not self-locking.

A Another challenge is ensuring a Backlash is because the loads on the actuator act, depending on the operating point can be changing.

Summarized The following problems arise in the prior art. Holding and changing the compression ratio ε act the operating forces due to the mass and gas forces opposite. The gas forces acting on the piston as a result of the power strokes result in time and depending on the crankshaft position, spatially variable reaction forces in the crankshaft bearing and thus temporally variable holding moment and / or holding forces on the actuator and the actuator. At the resulting holding moments or holding forces on the actuator it comes through the overlay the piston movements to zero crossings, d. H. first Positively directed holding moments have a short-term effect depending on the position of the piston in the opposite direction.

In 1 a diagram is shown in which on the high-value axis acting on the output shaft of an actuator holding torque relative to the time is shown. As can be seen from the diagram, during operation of the motor, at least approximately sinusoidal holding moments occur, which are displaced in one direction with respect to the zero line, so that the resulting holding torques, which are positively marked in the diagram, have a significantly higher maximum value than the negatively marked holding torques.

task

Object of the invention

Of the Invention is based on the object, an arrangement for changing the compression ratio in an internal combustion engine or to provide an internal combustion engine with such an arrangement, at or at which the actuator less exposed to strong mechanical loads is as usual, especially in the case of which the direction change of the load are defused.

Solution of the task

These The object is achieved by the claim 1 or solved by the features described in claim 18.

at the inventive arrangement are the during the engine operation on the actuator occurring vibrations completely or at least partially absorbed by the spring unit and Effectively cushioned, so that the actuator itself, is subjected to lower mechanical loads than in State of the art. The spring unit is for this purpose installed and dimensioned that the spring force the summary average Holding torque from the gas and mass forces of all cylinders counteracts.

When Spring unit are in particular mechanically operated spring units, such as coil springs, bow springs, tension and compression springs, but also storage facilities for storing potential energy, such as elastic memory elements, For example, molded elements made of an elastic material. alternative can also be pneumatic or hydraulic spring units Spring units or electrical storage devices for storage potential energy can be used.

Further advantageous developments of the invention will become apparent from the Description, the drawings and the dependent claims.

Preferably the spring unit is arranged and dimensioned so that the the actuating device acting holding forces and / or holding moments during engine operation only in one Act direction. The thus caused displacement of the holding forces or holding moments has the consequence that on the one hand, the mechanical Loads that in the prior art described the system changes cause it to be avoided. For another, the through the system changes resulting noise significantly reduced become.

at a particularly preferred embodiment of the invention Arrangement is the spring unit so with the actuator and / or coupled to the actuator that when adjusting the actuator for reducing the compression ratio a part of the applied by the actuator Energy is stored in the spring unit. As explained at the beginning, support the gas and mass forces the adjusting movement of the adjusting device in reducing the compression ratio, so that the actuator comparatively little force spend to adjust the actuator. To adjust the adjusting device when increasing the compression ratio the actuator must, however, the adjusting device adjust against the effect of gas and mass forces.

Alternatively, it is also possible to arrange and dimension the spring unit such that the holding forces acting on the actuating device and / or holding moments act at least approximately in a first predetermined direction up to a predetermined intermediate position of the spring unit, while in a further compression of the spring unit via the Intermediate position also act acting holding forces and / or holding moments in a deviating to the first direction of the second direction. This ensures that the adjusting device by the action of the spring unit in a Mittel- or intermediate position is kept, from which the actuator is moved by the action of the actuator. For this purpose, the spring unit can be coupled to the actuating device and / or adjusting device, for example via a lever arrangement.

According to the invention in this preferred embodiment, therefore, the actuator not only in reducing the compression ratio for adjusting the adjusting device, but beyond at the same time used for charging or biasing the spring unit. The values stored during the reduction of the compression ratio potential energy then increases while increasing the compression ratio used to support the actuating movement of the actuator. In this way it is possible to control the actuator smaller dimension.

alternative However, it is also possible for the development described above arrange the spring unit so that the spring unit increases the compression ratio a part of the adjustment the adjusting device applied by the actuator Energy stores and reducing the compression ratio the stored energy at least partially returns. To this Way is achieved that in case of malfunction of the actuator the actuator causes by the biasing force of the spring unit a harmless for engine operation compression ratio setting (fail-safe position).

Of Another is in a particularly preferred embodiment proposed, the arrangement additionally with a damping unit equipped with which the adjusting device and / or the actuating device is in active connection. With the help of the damping unit can be due to the operation of the internal combustion engine the actuator acting vibration loads be damped effectively, reducing the amplitudes of the total acting holding moments reduced and thereby swelling acting Strains on the various components of the arrangement reduced become.

at Use of such damping units can the damping unit and the spring unit in series or connected in parallel to each other with the adjusting device and / or the actuating device are in operative connection. The Damping unit can be designed as a separate device. However, it can also be integrated in the spring unit.

When Damping unit is for example a pneumatic or hydraulic damping element. Alternative or supplementary For this purpose, the damping unit also in the form of a mass-spring system be formed, which is comparable to a so-called torsional vibration damper is constructed, so an arrangement of one or more springs, which is or are coupled to a free-floating mass.

According to one particularly preferred embodiment is the adjusting device designed as an eccentric bearing arrangement for the crankshaft, with the crankshaft for adjusting the compression ratio about a parallel to the axis of rotation of the crankshaft extending eccentric axis is pivoted so that the distance of the axis of rotation of Crankshaft to the cylinders of the internal combustion engine for adjusting the compression ratio changes. The actuating device hereby serves to pivot the eccentric bearing arrangement the eccentric axis. The use of this eccentric bearing arrangement as an adjusting device has in the present invention in particular the advantage that the eccentric bearing assembly with appropriate Design a large part of the occurring gas and mass forces record and the actuator accordingly small can be dimensioned, since they only to a limited extent the necessary for holding the bearing assembly in the set position Holding forces or holding moments must generate.

at a particularly preferred embodiment of the invention Arrangement serves as a spring unit concentric with the eccentric axis of the Bearing arrangement arranged bow spring, which with the bearing assembly coupled to store and deliver potential energy. These Type of storage device has the advantage that when adjusting the bearing assembly about the eccentric axis serving as a spring unit Bow spring biased depending on the adjustment either is or the actuator during pivoting the bearing assembly supported. Furthermore, it is special advantageous if the bow spring frictional in a housing supported. Under frustrated in this context understood that the occurring at the bow spring during operation of the internal combustion engine Vibrations are damped by friction in which the Bow spring on the housing or provided for this purpose Along friction surfaces.

The bearing arrangement itself is preferably formed from a plurality of bearing elements in which together the crankshaft is mounted eccentrically. The bearing elements are in turn stored in corresponding bearings on the motor housing by sliding or roller bearings. For common adjustment of the bearing elements, an adjusting shaft is provided which is driven by the actuating device and is held. The coupling of the adjusting shaft with the bearing elements takes place, for example, via toothed segments provided on the bearing elements, which engage with toothings provided on the adjusting shaft, for example helical gears.

at this development of the bearing assembly is the at least one Spring unit preferably coupled to the adjusting shaft to the cushion vibrations occurring and when adjusting the Adjusting shaft by the actuator energy store or deliver in support of the actuator movement. The spring unit can in this development, for example, as at least be provided on the adjusting shaft bow spring, which is coupled to the adjusting shaft and, preferably frictionally supported in a housing.

Around to achieve a damping effect is also proposed to provide at least one friction element on the bow spring, with the bow spring is subject to friction in the housing supported.

Instead of or in addition to the described bow spring, the Storage device also arranged with at least one concentric with the adjusting shaft Spiral spring be equipped as a spring unit, which with the adjusting coupled and is supported in a housing. In which the windings of the coil spring can be made tight, can used the friction between the windings for damping become.

at an alternative development of the arrangement with eccentric Bearing assembly, the actuator at least a pneumatically or hydraulically actuated linear actuator on, whose actuating piston with at least one as a spring unit coupled elastic element is coupled to occurring vibrations cushion. Furthermore, the elastic element is preferably so on Linear actuator arranged that the elastic element when pressed of the linear actuator is biased as soon as the actuator the adjusting device for reducing the compression ratio adjusted, and the linear actuator by the introduced bias supported when the linear actuator the bearing assembly again against the gas and mass forces of the internal combustion engine Increase of the compression ratio adjusted. The linear actuator is preferably over in this embodiment a lever assembly coupled to the individual bearing elements.

After all It is proposed that the spring unit directly with the actuator to couple or to integrate into this. For example proposed, when using a servomotor as actuator, the motor shaft of the servomotor directly with the spring unit to pair. This can, for example, as deferred to the motor shaft Spiral spring be formed, which with its one end with the Motor shaft is connected and their end different, for example supported on a housing portion of the motor housing.

According to one In another aspect, the invention relates to an internal combustion engine with an inventive arrangement for changing the compression ratios.

embodiment

Short description of the drawing

The The invention will be described below with reference to the accompanying drawings on two Embodiments explained in more detail. It shows:

1 a diagram in which the curves of the acting on the conventional actuator of a four-cylinder engine holding moments are shown in relation to the time;

2 a schematic representation of the basic principle of the arrangement according to the invention for varying the compression ratio;

3 a diagram in which the torque curves of a four-cylinder engine without use and using the inventive arrangement are shown in relation to the time;

4 a partially sectioned side view of a first embodiment of an inventive arrangement;

5 a partially sectioned side view of a modification of the in 4 shown first embodiment; and

6 a partially sectioned side view of a second embodiment of an inventive arrangement.

Detailed description the drawing

In 2 is a schematic representation of the basic principle of an inventive arrangement 10 for varying the compression ratio in an internal combustion engine not shown in detail.

The order 10 has an adjusting device 12 on, with either the on the crankshaft 14 stored piston 16 relative to the cylinders 18 of Internal combustion engine or the engine block together with the cylinders 18 relative to the pistons 16 can be moved. By the relative procedure of the pistons 16 to the cylinders 18 the compression ratio can be adjusted depending on the engine parameters.

The adjusting device 12 is via an actuator 20 , For example, a servomotor, driven and, depending on the design of the actuator 12 also held in the desired position.

According to the invention, the actuating device 20 by a spring 22 for storing potential energy with the actuator 12 coupled. Parallel to the spring 22 is also a damping unit 24 connected.

As explained above, cause the movements of the piston 16 during operation of the internal combustion engine corresponding gas and mass forces coming from the crankshaft 14 or from the engine block to the actuator 12 be transferred and corresponding holding moments or holding forces on the actuator 20 cause.

In 3 These are sinusoidal holding moments considered over time, transmitted through the spring 22 and the damping unit 24 on the actuator 20 In comparison to the holding moments shown in dashed line are shown in solid line the curves of holding moments that switch without intervening the spring 22 and the damping unit 24 on the actuator 20 would work.

As 3 it can be seen, the holding moments in the inventive arrangement 10 by the action of the spring 22 moved away from the zero line upwards into the positive range, while at the same time the maximum amplitude of the holding moments due to the effect of the damping unit 24 is reduced.

It is characterized by the action of the spring 22 the actuating device 20 from the actuator 12 decoupled such that the at the adjusting device 12 acting vibrations only cushioned to the actuator 20 be transmitted. By shifting the holding moments in the positive area, the above-described system changes, which occurs in conventional arrangements for varying the compression ratio, avoided, so that the noise in the inventive arrangement 10 is significantly reduced. At the same time occurring voltage spikes in the components, in particular the actuator 20 , diminished by damping the amplitudes of the holding moments.

In 4 is a first embodiment of an inventive arrangement 110 to change the compression ratio. The order 110 has as a setting device 112 an eccentric bearing arrangement 126 in which the crankshaft 114 is stored in eccentric bearings. The eccentric bearing arrangement 126 is about a parallel to the axis of rotation of the crankshaft 114 extending eccentric axis 128 pivoting, causing the crankshaft 114 can be raised or lowered depending on the pivoting direction to either increase or decrease the compression ratio.

The bearing arrangement 126 is with several bearing elements 130 provided, of which in the 4 only one is recognizable. Each bearing element 130 is with a gear segment 132 provided with the bearing element 130 with an adjusting shaft 134 the actuator 120 engaged. The adjusting shaft 134 is by a servomotor, not shown in detail, the actuator 120 driven.

Furthermore, on the adjusting shaft 134 a coil spring 122 deferred, one end of which is fixed to the adjusting shaft 134 and the other end fixed to a housing section 136 the crankcase is connected. The spiral spring 122 acts on the coupling between the bearing assembly 126 and the actuator 120 in that occurring vibrations acting on the adjusting shaft 134 be transmitted from the coil spring 122 be absorbed and cushioned. The spring constant of the spiral spring 122 is chosen so that occurring vibrations are also damped to a limited extent.

To a smallest possible drive for the actuator 120 to provide, the coil spring 122 so used and biased that they are in the maximum raised position of the crankshaft 114 , in which the pistons specify the highest possible compression ratio, is at least approximately relaxed, while the coil spring 122 by adjusting the bearing assembly 126 in the maximum possible lowered position of the crankshaft 114 in which the pistons specify the smallest possible compression ratio, the maximum is preloaded. In addition, the coil spring can 122 be used as a limitation of the adjustment by sitting, for example, in the maximum biased position on block.

By this type of arrangement and biasing the coil spring 122 is also achieved that the occurring during operation gas and mass forces the biasing of the coil spring 122 support when the crankshaft 114 is moved to the maximum possible lowered position. The case in the coil spring 122 stored potential energy can then be at a renewed lifting of the crankshaft 114 be released to increase the compression ratio, thereby assisting the drive of the actuator 120 ,

Due to the effect of the spiral spring 122 Therefore, the drive can be relatively small dimensions, since the actuating movement of the crankshaft 114 against the gas and mass forces by the spiral spring 122 released potential energy during the adjustment is supported.

In 5 is a modified embodiment of the in 4 shown arrangement 110 shown in the place of the described coil spring 122 a so-called bow spring 140 is used. The bow feather 140 is on a rotationally fixed with the adjusting shaft 134 connected socket 142 mounted and supported in the circumferential direction of the adjusting 134 considered with their end faces on a housing section 136 from where it is frictionally applied with its peripheral surface at least in sections. When vibrations occur on the adjusting shaft 134 springs the bow spring 140 in the circumferential direction, at the same time their peripheral surface on the housing portion 136 slides along, which additionally an attenuation effect is achieved. Instead of just a bow spring 140 It is also possible, several bow springs in a corresponding manner next to each other on the adjusting 134 provided. It is also possible to use the bow spring 140 with reference to 4 described spiral spring 122 to combine.

Alternatively, the above-described bow spring also directly on the bearing elements of the eccentric bearing assembly 126 be provided.

6 shows a second embodiment of an arrangement 210 for changing the compression ratio. Also this arrangement 210 is with an eccentric bearing arrangement 226 for the crankshaft 214 fitted. However, in this embodiment, the coupling between the actuator takes place 220 and the bearing assembly 226 via a lever arrangement 244 , which to the bearing elements 230 is articulated. The lever arrangement 244 is powered by a pneumatically or hydraulically controlled cylinder 246 operated as the linear actuator of the actuator 220 serves.

In the cylinder 246 is a compression spring 222 taken up with the piston 248 of the cylinder 246 connected is. As soon as the piston 248 in the cylinder 246 is extended, causing the crankshaft 214 lowered and the compression ratio is reduced, the compression spring 222 upsets and stores potential energy. Will now be the crankshaft 214 raised again to increase the compression ratio by the piston 248 of the cylinder 246 is retracted, supports the previously compressed compression spring 222 the adjusting movement of the cylinder 246 , At the same time, in every position of the cylinder 246 occurring vibrations from the compression spring 222 as well as in the cylinder 246 cushioned air or liquid column. By additionally providing corresponding throttle bores in the piston 248 In addition, an additional damping effect in the cylinder 246 be achieved.

The previously described two embodiments only a very small selection of the many possible constructive reactions of the invention Principle. For example, instead of mechanical Springs also used pneumatic or hydraulic spring elements become. It is also possible, suitable electrically operated acting as spring elements devices, such as small actuators, electric solenoids, permanent magnets or the like to provide. In the same way, suitable mechanical and / or also provided pneumatic or hydraulic damping elements become. The spring elements and damping elements can also directly to the controls be integrated to achieve the desired effects.

10

arrangement

12

setting device

14

crankshaft

16

piston

18

cylinder

20

actuator

22

spring unit

24

damping unit

110

arrangement

112

setting device

114

crankshaft

120

actuator

122

spiral spring

126

bearing arrangement

128

eccentric

130

bearing element

132

toothed segments

134

adjusting

136

housing section

138

bow spring

140

Rifle

210

arrangement

212

setting device

214

crankshaft

220

actuator

222

compression spring

244

lever assembly

246

cylinder

248

piston

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 29719343 U1 [0005]
• DE 3004402 A1 [0005]
• - DE 3601528 A1 [0005]
• - DE 3644721 A1 [0005]

Claims (18)

Arrangement for varying the compression ratio in an internal combustion engine, having an adjusting device ( 12 ; 112 ; 212 ) for changing the relative position of the pistons ( 14 ) to the cylinders ( 18 ) of the compression ratio adjusting internal combustion engine, and one with the adjusting device ( 12 ; 112 ; 212 ) Actuator ( 20 ; 120 ; 220 ) for actuating the adjusting device ( 12 ; 112 ; 212 ), characterized by at least one spring unit ( 22 ; 122 ; 138 ; 222 ), which by the operation of the internal combustion engine to the actuator ( 12 ; 112 ; 212 ) acting gas and mass forces against the actuator ( 20 ; 120 ; 220 ) At least partially cushioning. Arrangement according to claim 1, characterized in that the spring unit ( 22 ; 122 ; 138 ; 222 ) is arranged and dimensioned so that the at the actuator ( 20 . 120 ; 220 ) acting holding forces and / or holding moments act only or essentially only in one direction. Arrangement according to claim 1, characterized in that the spring unit ( 22 ; 122 ; 138 ; 222 ) is arranged and dimensioned such that the holding forces acting on the actuating device and / or holding moments up to a predetermined intermediate position of the Federein unit ( 22 ; 122 ; 138 ; 222 ) act at least approximately in a first predetermined direction, while in a further compression of the spring unit ( 22 ; 122 ; 138 ; 222 ) act beyond the intermediate position, the acting holding forces and / or holding moments in a deviating from the first direction second direction, wherein the spring unit ( 22 ; 122 ; 138 ; 222 ) is preferably coupled via a lever arrangement with the actuating device and / or adjusting device. Arrangement according to claim 1, 2 or 3, characterized in that the spring unit ( 22 ; 122 ; 138 . 222 ) in reducing the compression ratio, a part of the adjusting device ( 12 ; 112 ; 212 ) from the actuator ( 20 ; 120 ; 220 ) stored energy and in increasing the compression ratio in support of the actuating movement of the actuator ( 12 ; 112 ; 212 ) at least partially releases the stored energy. Arrangement according to claim 1, 2 or 3, characterized that the spring unit when increasing the compression ratio a part of when adjusting the actuator of the actuator applied energy stores and reducing the compression ratio the stored energy at least partially returns. Arrangement according to one of claims 1 to 5, characterized in that a plurality of spring units ( 22 ; 122 ; 138 ; 222 ) are provided for storing the potential energy and that the spring units ( 22 ; 122 ; 138 ; 222 ) are connected in series and / or parallel to each other. Arrangement according to one of claims 1 to 6, characterized in that the at least one spring unit is a spiral spring ( 22 ; 122 ; 222 ), which limits the displacement by blocking. Arrangement according to one of the preceding claims, characterized in that at least one with the adjusting device ( 12 ; 112 ) and / or the actuating device ( 20 ) in operative connection damping unit ( 24 ; 136 ) for damping by the operation of the internal combustion engine on the actuator ( 12 ; 112 ) acting vibration loads is provided. Arrangement according to claim 8, characterized in that the at least one damping unit ( 24 ) and the at least one spring unit ( 22 ; 138 ) in series and / or in parallel with the adjusting device ( 12 ; 112 ) and / or the actuating device ( 20 ; 120 ) are in operative connection. Arrangement according to one of the preceding claims, characterized in that the adjusting device ( 112 ; 212 ) an eccentric bearing arrangement ( 126 ) for the crankshaft ( 114 . 214 ), which is the crankshaft ( 114 . 214 ) for adjusting the compression ratio about a parallel to the axis of rotation of the crankshaft ( 114 ; 214 ) extending eccentric axis ( 128 ) such that the distance of the axis of rotation of the crankshaft ( 114 . 214 ) to the cylinders of the internal combustion engine for adjusting the compression ratio changes, and that the actuator ( 120 ; 220 ) with the eccentric bearing arrangement ( 126 ) for pivoting the eccentric bearing assembly ( 126 ) about the eccentric axis ( 128 ) is in operative connection. Arrangement according to claim 10, characterized that the spring unit at least one concentric with the eccentric axis the bearing assembly arranged bow spring is, which with the bearing assembly is coupled to store and release potential energy and preferably frictionally supported in a housing. Arrangement according to claim 10, characterized in that the eccentric bearing arrangement ( 126 ) of several bearing elements ( 130 ) for the crankshaft ( 114 ) is formed, that each bearing element ( 130 ) by an adjusting shaft ( 134 ) with the common actuator ( 120 ), and that the spring unit ( 122 ) with the Ver adjusting shaft ( 134 ) is coupled. Arrangement according to claim 12, characterized in that the spring unit at least one of the adjusting shaft ( 134 ) provided bow spring ( 138 ), which with the adjusting shaft ( 134 ) is coupled and, preferably frictionally, in a housing ( 136 ) is supported. Arrangement according to claim 13, characterized in that a damping unit ( 24 ) in the form of at least one on the bow spring ( 138 ) provided frictional element is formed, with which the bow spring ( 138 ) in the housing ( 136 ) is supported in sections. Arrangement according to claim 12, 13 or 14, characterized in that at least one of the spring units concentric with the adjusting ( 134 ) arranged spiral spring ( 122 ), which with the adjusting shaft ( 134 ) and in a housing ( 136 ) is supported. Arrangement according to one of the preceding claims, characterized in that the actuating device ( 220 ) at least one pneumatically or hydraulically actuated linear actuator ( 246 ), whose actuating piston ( 248 ) with at least one spring unit ( 222 ) is coupled in such a way that the actuating device ( 220 ) the spring unit ( 222 ) when the actuating device ( 220 ) the adjusting device ( 212 ) to reduce the compression ratio. Arrangement according to one of the preceding claims, characterized in that the actuating device ( 20 ) has at least one servomotor whose motor shaft for adjusting the Stelleinrich device ( 12 ) is in operative connection with this, and that the motor shaft with the spring unit ( 22 ) is coupled. Internal combustion engine with an arrangement according to one of the preceding claims for altering the Compression ratio.