WO2012080464A1

WO2012080464A1 - Drive system

Info

Publication number: WO2012080464A1
Application number: PCT/EP2011/073044
Authority: WO
Inventors: Herbert Klement
Original assignee: Herbert Klement
Priority date: 2010-12-16
Filing date: 2011-12-16
Publication date: 2012-06-21
Also published as: DE102010063289A1

Abstract

The present invention relates to a drive system (1), which has a first two-stroke internal combustion engine (2) having a linearly guided piston (3) and an additional two-stroke internal combustion engine (2) having a linearly guided piston (3). The piston guides of the two-stroke internal combustion engines (2) are all arranged parallel to each other. The power strokes of the individual two-stroke internal combustion engines (2) are phase-shifted relative to each other in such a way that the vibrations of the drive system (1) resulting from the piston motions are minimized. The pistons (3) are movably coupled to a swashplate (4), which in turn is rigidly connected to a drive shaft (5). Because the linearly guided pistons (3) are thus coupled to a swashplate (4), the translational motion of the pistons (3) is converted to a rotational motion of the swashplate (4) and of the drive shaft (5) rigidly connected to the swashplate.

Description

drive system

The present invention relates to a drive system with a two-stroke internal combustion engine with a linearly guided piston.

From the literature various concepts for drive systems are known which have a linear piston guide. For example, a two-stroke free-piston engine in its simplest construction only comprises one moving element, namely a piston. Since this performs only a linear movement, energy losses due to friction and forces that do not act parallel to the piston axis are minimized. The term piston axis designates here and in the following text always the piston longitudinal axis. The small number of moving or moving elements also helps to minimize energy losses and thus increase efficiency. Due to the low number of wearing parts, the life of this maintenance-friendly type of motor increases. The possibility proves to be particularly advantageous to construct a very compact, cost-effective drive system. Such a two-stroke free-piston engine is also known as Stelzer engine and described in DE 3029287.

A disadvantage of drive systems based on a two-stroke process with a linear piston guide are the vibrations of the drive system resulting from the piston movements. The momentum of the piston is transferred to the drive system and causes it to vibrate. Such vibrations can lead to strong vibrations and thus to an increased material load and increased noise emission.

If you want to use a drive system such as the one described above, for example, to drive a car, the translation movement of the linearly guided piston along the piston axis must be converted loss-free as possible in a rotational movement. This fact is due to the necessity that for driving a car usually a rotational movement in the form of the rotating wheels is necessary. This need exists in an analogous manner for the drive of other means of locomotion in their usual form such as ships or helicopters due to the rotational movement of the propellers or rotor blades. It would therefore be advantageous if a drive system based on the idea of a two-stroke internal combustion engine with a linearly guided piston were available, in which the vibrations of the drive system resulting from the translatory movement of the piston are minimized. In addition, it would be advantageous if the translational movement of the piston were converted efficiently into a rotational movement.

Based on the described prior art, this task is solved in that for the drive system in addition to a first two-stroke internal combustion engine with a linearly guided piston at least one further two-stroke internal combustion engine is provided with a linearly guided piston, the piston guides of the internal combustion engine parallel to each other are arranged. The working cycles of the individual internal combustion engines are phase-shifted relative to one another such that the vibrations of the drive system resulting from the piston movements are minimized. For example, if two two-stroke internal combustion engines are used, the two pistons should be in anti-phase, i. 180 ° out of phase, be moved.

By using more than one linearly guided piston, it is possible that the individual pulses of the pistons in their entirety add up to a negligible total impulse. As a first approximation, it can be assumed that the piston movement can be approximately described by a sinusoidal oscillation. In order to obtain a destructive interference of the sinusoids, for example, for a number N of identically constructed pistons, the sinusoidal oscillations of the pistons must each be shifted relative to each other by an integer multiple of the phase. More specifically, the individual pistons may be numbered in any order, with the Nth piston being one phase out of phase with the first piston. Such a relative phase shift between the oscillations causes the oscillations to cancel each other out when they are superimposed. As a result of the phase shift just described, the oscillations of the drive system are minimized, resulting in quiet and low-wear running of the drive system.

In principle, it would be possible to drive the individual two-stroke internal combustion engines different elements. In particular, when the linear movement of the piston is to be converted into a rotational movement of a drive shaft, however, it is recommended that the individual two-stroke internal combustion engines drive the same element.

In order to be able to convert the linear movements of the pistons into a rotational movement for driving a drive shaft, it is therefore provided according to a preferred embodiment that the pistons of the two-stroke internal combustion engines drive a swash plate, which in turn is connected to a drive shaft. In this case, the swash plate axis is tilted relative to the drive shaft axis, so that the swash plate, when in a direction parallel to the drive shaft axis, a force is exerted on the swash plate, this evades the force by a rotational movement and thereby causes a rotational movement of the drive shaft. The term drive shaft axis here and in the text always refers to the drive shaft longitudinal axis.

Due to the tilted arrangement of the swash plate is always a portion of the swash plate of a two-stroke internal combustion engine disposed closer than another portion of the swash plate. Now, if a force is exerted by the piston on the region of the swash plate, which is arranged closer to the two-stroke internal combustion engine, the swash plate and thus the drive shaft rotates until the piston engages a portion of the swash plate, which further from the two-stroke internal combustion engine is removed. In such a swash plate embodiment, it is possible to convert the linear movement of the coupled pistons into only a small amount of rotational movement, which can be used, for example, to drive the wheels of a car.

As the swashplate moves together with the drive shaft, the piston should be movably coupled to the swashplate so that the swashplate and piston can rotate relative to each other. The pistons can exert tensile or compressive forces on the swash plate. Most preferably, the pistons are coupled to the swash plate so that they can alternately exert tensile and compressive forces on the swash plate. These tensile and compressive forces cause the swash plate and with it the drive shaft are set in rotation. The cause of this rotational movement lies in the fact that the forces exerted by the pistons on the swashplate can be decomposed into a first force component perpendicular to the swashplate and a second force component located in the swashplate plane. It is this second force component that causes the swashplate to rotate.

In a further preferred embodiment it is provided that the pistons are coupled via a coupling disk to the swash plate, wherein the coupling disk and the swash plate can perform relative to each other a rotational movement about the drive shaft axis. Therefore, while the swash plate rotates with the drive shaft, the coupling disc will not rotate. In this case, the coupling disc can surround the swash plate such that it is movably mounted both on the front and on the rear side of the swash plate. The linear movement of the piston leads to a tilting of the coupling disc relative to Drive shaft axis. This tilting of the coupling disc in turn leads via the two-sided, movable support to the swash plate to a rotational movement thereof.

In a further preferred embodiment, the coupling disc has substantially part-spherical recesses, in which engage the convex ends of the piston. Such a connection between the ends of the piston on the one hand and the coupling disc on the other hand ensures effective power transmission between the piston and the coupling disc.

This type of coupling is particularly advantageous when the piston ends are held by the coupling discs substantially positive fit in the part-spherical recesses, so that the piston in a movement away from the coupling disc take the same, so that by the piston, a tensile force on the coupling disc can be applied.

By this measure, therefore, both a pressure and a tensile force can be applied to the disc of all the pistons, whereby the drive system is effectively utilized.

For the conversion of the translation movements into a rotational movement, it is advantageous if the drive system has at least three pistons and thus also at least three two-stroke internal combustion engines, which are optionally coupled via a coupling disc to the swash plate. Thus, it can be ensured that in any position of the swash plate all pistons are at the same time in a dead center.

By dead center, this is to be understood as meaning a position of the piston end coupled to the coupling disk, in which the force component responsible for the rotation of the swashplate, the force exerted by the piston on the swashplate, is directed in the swashplate plane parallel to the radius of the swashplate. Are all piston ends at the same time in such a dead center, this leads to the fact that no rotational force is exerted on the swash plate. If you try to start the drive system in such a piston position, the piston can not be set in motion even under any amount of force. The reason for this lies in the fact that because of the prevented rotation of the swash plate via the coupling described above, the translational movement of the piston is prevented. This problem can be solved in that the number of coupled to the swash plate piston is at least three. Alternatively, an electric starter or a similar device may be provided to move the drive shaft during the starting process in motion. When using such a device a dead center position of the piston is avoided in the course of the starting process. Under this condition, it is advantageous if an even number of as many as possible of the tumble is provided disc coupled piston. In this case, the vibrations of the drive can be minimized with little technical and thus financial expense by the working cycles of two internal combustion engines are phase-shifted by 180 ° to each other. As a result, each of the pulses of the pistons of two internal combustion engines cancel each other.

A symmetrical arrangement of the two-stroke internal combustion engine about the drive shaft axis leads to the fact that all piston axes can have the same distance to the drive shaft axis. Thus, the points of attack of the piston ends are distributed symmetrically to the swash plate and the coupling plate. Such an arrangement of the two-stroke internal combustion engine has the advantage that the force acting on the swash plate is distributed symmetrically and thus evenly. This ensures on the one hand a possible constant torque, on the other hand is guaranteed by the fact that due to the uniform force, the load of the swash plate is as uniform as possible. Such a uniform loading of the swash plate results in permanent, section-wise overloading of the swash plate being avoided, thus increasing its service life.

If all two-stroke internal combustion engines, which are covered by the drive system, identical, so this offers the possibility to build the entire drive system completely symmetrical. Such a symmetrical structure and symmetrically acting forces connected to it ensure that, on the one hand, the vibrations of the drive system can be efficiently minimized and, on the other hand, one-sided signs of wear are avoided.

A drive system comprising a plurality of two-stroke internal combustion engines coupled to a swash plate has the characteristic that the torque applied by the drive system is proportional to the number of two-stroke internal combustion engines included in the drive system. By such a construction, it is possible that mean torque from the stroke of the piston, d. H. from the maximum distance that can cover the piston ends along the piston axis to decouple. Such decoupling of stroke and torque makes it possible to generate a large torque even with a relatively small stroke. A small piston stroke allows the construction of very compact drive systems.

Such drive systems can be operated in small speed ranges due to the comparatively large average torque. A small speed range means that only a small number of combustion processes take place per unit of time. Thus, the consumption of fuel decreases per time. The result is a propulsion system which is advantageous both in terms of its economy and its environmental friendliness. Further advantages, features and possible applications will become apparent from the following description of an exemplary embodiment and the associated figures. FIG. 1 shows an exemplary embodiment of a drive system with two two-stroke internal combustion engines, which are movably coupled to a swash plate via a coupling disk,

2 shows a detailed view of the coupling of the two pistons to the swash plate of FIG

1.

It should be understood that both the foregoing general description and the following detailed description are exemplary and illustrative only and are intended to provide further explanation of the claimed invention. FIG. 1 shows a drive system 1 comprising two two-stroke internal combustion engines 2 coupled to a swash plate 4. The swash plate 4 is in turn fixedly coupled to a drive shaft 5. The illustration is a cross-sectional view of a section along the two piston axes through the piston centers. The illustrated two-stroke internal combustion engines 2 each comprise a linearly guided multistage piston 3, which has in the middle a disc 9 which moves linearly in a pre-compression chamber 10 with the piston 3. In addition to the pistons 3 and the precompression chamber 10, the two-stroke internal combustion engines 2 each have two combustion chambers 11. These combustion chambers 11 are connected by overflow openings 12 with the precompression chamber 10.

In order for the air-fuel mixture to be combusted to enter the two-stroke internal combustion engines 2, the precompression chamber 10 has an inlet opening 13. Furthermore, there are at the combustion chambers 11 outlet openings 14, which can be opened and closed via controllable valves 15. The ends of the piston 3 sit in recesses 8 of a coupling disc 6. This clutch disc 6 surrounds a swash plate 4. The coupling disc 6 is movably mounted on the front and back of the swash plate 4. The movable mounting of the coupling disk 6 to the swash plate 4, for example via ball bearings 16. The swash plate 4 is in turn fixedly coupled to a drive shaft 5. The piston axes have the distance R to the drive shaft axis. If the pistons 3 are moved back and forth along the piston axes as a result of the combustion processes in the combustion chambers 11, they tilt the coupling disk 6 relative to the drive shaft axis. This tilting of the coupling disk 6 in turn leads to a rotation of the swash plate 4 due to the bilateral, movable coupling of the coupling disk 6 to the swash plate 4. The rotation of the swash plate 4 in turn forces a rotation thereof via the fixed coupling to the drive shaft axis 5. This rotating drive shaft 5 can be used for example for driving the wheels in conventional embodiments of cars application. FIG. 2 shows a detail view from the cross-sectional view of FIG. This second view represents in detail the coupling of the pistons 3 to the swash plate 4. The ends 7 of the pistons 3, which are seated in depressions 8 in the coupling disk 6, can be seen. Also shown is the coupling disc 6 which surrounds the edge of the swash plate 4 such that it is mounted in the region of the edge of the swash plate 4 on the front and rear side thereof movable on the same. In this case, the movable bearing takes place on both sides via ball bearings 16. The swash plate 4 is in turn firmly connected to the drive shaft 5. By this fixed connection, the rotation of the swash plate 4 is transmitted to the drive shaft 5.

For purposes of the original disclosure, it is to be understood that all such features as will become apparent to those skilled in the art from the present description, drawings, and claims, even if concretely described only in connection with certain other features, both individually and separately any combinations with other features and feature groups disclosed herein are combinable, as far as this has not been expressly excluded or technical conditions make such combination impossible or pointless. On the comprehensive, explicit representation of all conceivable combinations of features is omitted here only for the sake of brevity and readability of the description.

While the invention has been illustrated and described in detail in the drawings and the foregoing description, such illustration and description is exemplary only and is not intended to limit the scope of the invention as defined by the claims. The invention is not limited to the disclosed embodiments.

Modifications of the disclosed embodiments will be apparent to those skilled in the art from the drawings, the description, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain features are claimed in different claims does not exclude their combination. Reference signs in the claims are not intended to limit the scope of protection. LIST OF REFERENCE NUMBERS

1 drive system

2 two-stroke internal combustion engines

3 pistons

4 swash plate

5 drive shaft

6 coupling disc

7 piston end

8 deepening

9 disc

10 precompression chamber

11 combustion chamber

12 overflow opening

13 inlet opening

14 outlet opening

15 controllable valve

16 ball bearings

Claims

Patent claims

1. Drive system (1) consisting of a two-stroke internal combustion engine (2) with a linearly guided piston (3), characterized in that a further two-stroke internal combustion engine (2) with a linearly guided piston (3) is provided, wherein the piston guides the two-stroke internal combustion engines (2) are all arranged parallel to one another and the working cycles of the individual two-stroke internal combustion engines (2) are out of phase with each other so that the oscillations of the drive system (1) resulting from the piston movements are minimized.

2. Drive system (1) according to claim 1, characterized in that the pistons (3) to a swash plate (4) are coupled, which in turn is fixedly connected to a drive shaft (5).

3. Drive system (1) according to claim 2, characterized in that the piston (3) to the swash plate (4) via a coupling disc (6), which surrounds the swash plate (4) are coupled, wherein the coupling disc (6) the front and back of the swash plate (4) is movably mounted.

4. Drive system (1) according to claim 3, characterized in that the ends (7) of the piston (3) in recesses (8) in the coupling disc (6) abut.

5. Drive system (1) according to claim 4, characterized in that the ends (7) of the piston (3) in a direction parallel to the piston axis are positively connected to the coupling disc (6).

6. Drive system (1) according to one of claims 2 to 5, characterized in that the drive system (1) has at least three, but preferably an even number of two-stroke internal combustion engines (2), each having a piston (3) is coupled to the swash plate (4).

7. Drive system (1) according to one of claims 2 to 6, characterized in that the two-stroke internal combustion engines (2) are arranged symmetrically about the drive shaft axis, so that all piston axes have the same distance (R) to the drive shaft axis. Drive system (1) according to one of claims 1 to 7, characterized in that the drive system (1) comprising two-stroke internal combustion engines (2) are all identical.

Drive system (1) according to one of claims 1 to 8, characterized in that the of the drive system (1) applied mean torque is proportional to the number of the drive system (1) comprises two-stroke internal combustion engine (2).