The invention relates to an internal combustion engine as per the preamble of claim 1.
Radial engines are known in which the cylinders with pistons are arranged in a star shape and the piston rods drive a crankshaft. A special type of radial engine is the rotary engine in which the crankshaft is stationary and the cylinders with pistons rotate.
Also known are rotary engines such as the Wankel engine in which a rotor rotates in an elliptical housing with epitrochoidal chambers, which rotor follows the ellipsoidal shape. As the rotor moves, the volumes of the individual chambers vary, and the four strokes of the engine are carried out during one rotation of the rotor, with sub-optimal segmentation. The elliptical shape generates differences in the chamber volumes, and the four working strokes thereby take place. The engines, and conventional internal combustion engines with pistons, have in common the fact that the combustion in the cylinder moves the piston, with the drive force being generated in this way.
It is an object of the invention to provide an internal combustion engine which, with a simple construction and smooth running behavior, has a high degree of efficiency. It is also an object of the invention to avoid the elliptical shape with the aim of maximum chamber sealing, reducing vibrations to a minimum and simplifying construction.
The objects are achieved according to the invention by means of the characterizing part of claim 1.
New features here are inter alia that the combustion of the air/gas mixture no longer takes place directly in the cylinders, and therefore the pistons no longer serve to provide drive directly, but the cylinders with pistons supply the additional combustion chambers with the compressed air/gas mixture. The rotor is driven by the gas flowing out of the combustion chamber, which is situated outside the rotor, after ignition.
As a result of the separation of compression and combustion, efficiency is increased, vibrations are reduced and wear is reduced. The compression and combustion processes can be optimized in separate regions of the engine.
The rotary-piston internal-combustion engine is distinguished in that it has small external dimensions, is light in weight and yet is highly powerful and nevertheless is economical, offers a wide spectrum for the control of the engine power, has a low fuel consumption and can burn fuels with a relatively high ignition point, such as for example hydrogen.
Further advantageous embodiments of the invention are listed in the subclaims.
According to the invention, the rotary-piston engine has a circular shape of the rotor and is constructed with an axis which is offset from the center C. This eliminates the complicated elliptical movement and permits good sealing of the individual working chambers.
The intake, compression and ignition of the air/fuel mixture and the discharge of the exhaust gases are carried out by means of the difference in the distances of the axis, which is offset from the center (C) of the rotor at the point B (center B), of the piston group to the periphery of the rotor. The intake takes place in the sector of maximum radius (r max) and the ignition of the air/fuel mixture and the discharge of the exhaust gases are carried out in the sector of minimum radius (r min) in one rotation of the rotor. The force generated as a result of the ignition is aligned tangentially in the direction of rotation of the rotor, which direction of rotation is predefined by the combustion chamber, the piston group and the offset center (B).
Advantageous exemplary embodiments of the invention are illustrated in the drawings and are described in more detail in the following. In the drawings:
In the figures, identical parts are fundamentally provided with the same reference symbols.
The rotary-piston internal combustion engine, composed of three or more interacting, liquid-cooled housings 1 which are arranged parallel to one another, has—according to FIGS. 1 to 3—in each case one housing 1 to which are attached a spark plug 2, and exhaust gas opening 3 and an intake opening 4. In the housing 1, the rotor 5 is formed with two ring gears 14. The segments 9 are attached to the rotor 5 at both sides of each individual working chamber 11 of the cylinders 6, which segments 9 serve to seal the working chambers 11. Those parts of the cylinders 6 which are moveably held in the rotor 5 are spherical at the outside, thereby performing the function of a ball joint.
The cylinders 6 are radially moveable and orbitally traversing and slide on the pistons 8 which are provided with smaller pistons (13) (expanders) and are themselves sealed off by the segments 9. The pistons 8 are mounted axially so as to be moveable independently of one another, as shown in
Top dead center of each piston is reached in the region where the discharge of the exhaust gases begins (
The cylinders 6 which are moveably held in the rotor 5 in the manner of balls act as compensating arms (angular compensators) which compensate the angled transitions to the different orbital positions which are determined by the offset center B and the circular shape of the rotor 5.
A smaller piston 13 is provided in the working chamber 11 of each cylinder 6, which smaller piston 13 serves to compensate the different loading torques at the different predefined powers up to the time at which the exhaust gases are discharged. The smaller piston 13 does not have any influence on the indicated pressure (pressure) formed in the working chamber 11. The movement is transmitted tangentially by means of pressure on the rotor 5 in its movement direction. The movement direction is predefined by the structure of the combustion chamber 17 in the housing 1 and by the piston group which is offset from the center C of the rotor 5 and is mounted in the housing 1,
The cylinder path (working volume) is varied, and the power of the engine during its working cycle can be varied as a result, with a change in the position of the offset center B from point B to another point (this can be controlled automatically). As can be seen in
A=F cos φ φ=ωt
F=φt f=rφ
A=Work
F=Force
ω=Angular speed
φ=Rotational angle
t=Time
l=the curve (path) from the combustion chamber 17 to the discharge opening 3
Z=Transmission number
For a constant volume of the working chamber 11 during the working process H, the present invention provides the desired indicated pressure, which corresponds to the predefined force F which acts on the rotational angle φ for a certain time t, with a significantly lower fuel quantity.
The function of the engine is provided once the starter is activated and the rotor 5 rotates. As a result of the structural differences in the distance from the periphery of the is rotor 5 to the axis 10 which is offset from the center C, the cylinders 6 vary the volumes of the working chambers 11 and, as a function of their contact points, the five working processes (see
As mentioned in the introduction (see
The annular piston 16 serves to carry out the intake of air in the sector of maximum radius (r max, see
At standstill, the rotor 5 has a certain structural mass which has a lower overall value than during rotation. The space from the inside of the rotor 5 is filled once with oil. The rotation causes centrifugal forces which distribute the oil on the inner wall of the rotor 5.
The rotor 5 has a structurally predefined relief shape of the inner wall. This causes the vaporization of the oil back into the interior space of the engine. As a result, a new, higher value of the mass of the rotor 5 is generated during rotation. This permits a relatively low level of energy consumption as the engine is started and a relatively high torque during working operation of the engine.
The invention relates to internal combustion engines of the rotary-piston type and can be used in automobile, aircraft and ship construction for driving wheels, generators, pumps and for driving various-gearings and mechanisms.
Once the rotary-piston engine is started, the rotor 5 is set into a right-hand rotational movement, with the volume of the working chamber 11 remaining constant during the working process (ignition of the air/fuel mixture in the combustion chamber 17).
At the instant, the piston 8 does not carry out any retracting movement. The pistons 8 serve only to suck air/fuel mixture into the cylinders 6, to compress the air/fuel mixture into the combustion chamber 17 and to discharge exhaust gases. Each individual piston 8 is mounted independently of the others. The entire piston group rotates about the axis 10 which is offset from the center C.
The ignition of the air/fuel mixture takes place outside the working chambers 11, specifically in the combustion chamber 17. At the instant, the piston 8 which has compressed the air/fuel mixture into the combustion chamber 17 forms an angle of 70° in relation to the rotor. The force F generated during the detonation is directly distributed tangentially to the rotor 5 by means of pressure. The piston 8 is not set into a retracting motion as a result of the detonation, as can be seen from
The rotary-piston internal combustion engine is composed of 3 rotors 5 and 3 piston groups 8/1, 8/II, 8/111 with the associated cylinders 6, in total 9 pistons 8. Each piston 8 is positioned in a structurally predefined fashion in relation to the others in such a way that an angle of 40° is formed between the pistons 8. This means that, as the engine is started, ignitions are carried out at intervals of 40°. The angular spacing is correspondingly proportionally reduced, in the possible case of a design of the engine with 4 rotors 5, to 30° (for example: in the case of 5 rotors 5, to 24°).
High rotational speeds are obtained at the output shaft 15, which meshes directly with the rotor 5 at its periphery, at a low rotational torque of the engine; this is possible without any complicated designs such as for example step-down gearings.
It is finally to be stated that, by means of the invention, a rotary-piston internal combustion engine has been developed which, in contrast to a Wankel engine, does not carry out any elliptical movement, and also has structural advantages over the Wankel engine, including: optimum sealing of the working chambers 11; low energy consumption when starting the engine; lighter in weight and more powerful during operation; small engine size; good dynamic equalization; economical; automatic user-oriented control of the engine power according to requirements, and therefore fuel consumption which can be selected depending on the situation; capable of burning fuels with a relatively high detonation point, such as hydrogen.
Number | Date | Country | Kind |
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05002570.9 | Feb 2005 | EP | regional |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP06/00312 | 1/16/2006 | WO | 00 | 8/8/2007 |