EP2065560A2 - Internal combustion engine - Google Patents

Abstract

The engine has a rotor housing (1) with a circular cross section, in which two pair of pistons (5-8) run in a rotation movement. A gear (14) has a non-circular hollow wheels (3, 4) arranged in an inner side of a moving path of the pistons, where the wheels exhibit a main axis and secondary axis. The hollow wheels are connected with the pair of pistons in a fixed manner. An inner wall of the rotor housing is curved in a toroid shape, and the hollow wheels exhibits convex sections in the area of auxiliary vertices, which are provided as end points of the secondary axis.

Description

The invention relates to an internal combustion engine according to the preamble of claim 1.

Internal combustion engines are currently for the most part designed as reciprocating engines. The disadvantages of this engine concept, which arise due to the reciprocating parts, such as inertial forces and moments, frictional losses and the like, are accepted, since the available alternatives have other disadvantages. For example, the concept of the Wankel engine has prevailed only in marginal areas.

As a further alternative to reciprocating engines so-called oscillating piston engines have become known. In these oscillating piston engines usually rotate two pairs of pistons in a housing with a circular cross-section, which is enforced by a special mechanism, an oscillating angular velocity of the piston pairs. As a result, the angular distance between the pistons of the piston pairs fluctuates cyclically, which can be utilized for carrying out the combustion process. Rotary piston engines of the type described are, for example, from GB 1 034 023 A , of the US 4,419,057 A , of the FR 2 730 274 A or the US 3,858,560 A known. The oscillating angular velocity of the Kolbepaare is achieved in these known solutions by various types of lever mechanisms, which are usually arranged laterally next to the rotor housing. These lever mechanisms make the known internal combustion engines complex and complex and usually lead again to inertial forces due to reciprocating parts, which partially negates the conceptual advantages of this type of internal combustion engine.

Furthermore, solutions have become known which at least partially avoid the disadvantages described above. Gear drives are used to cause the uneven piston movement. In this case, at least one non-circular, usually elliptical gear is engaged with an eccentrically mounted gear to form a transmission with a variable transmission ratio. Such internal combustion engines are in the WO 01/34944 A , of WO 95/17582 A , of the US 4,028,019 A , of the DE 197 44 591 A , of the DE 27 39 326 A or the US 3,302,625 A described. The disadvantage here, however, that relatively massive gear are required to ensure the required functionality. These transmissions are usually arranged next to the rotor housing and require appropriate space. In general, it is only possible to supply one or two rotor housings or piston pairs with one transmission. In order to connect several piston pairs mechanically, therefore, expensive additional gear are required to cause friction losses and stress space.

The RU 2 257 476 C shows an oscillating piston engine with two pairs of pistons, which are connected via gears with elliptical internal gears with a shaft. In the disclosed solution, on the one hand, there is the disadvantage that the achievable phase difference between the pairs of pistons is only relatively small, so that a compression ratio that is too low for internal combustion engines results. Moreover, the annular cylindrical rotor housing leads to significant problems in the sealing when the machine is to be operated as an internal combustion engine.

The primary object of the present invention is to avoid these disadvantages and to provide a practically usable internal combustion engine which has a sufficient compression ratio and which can be sealed in a safe and cost-effective manner.

Another object of the invention is to avoid these disadvantages and to develop an internal combustion engine of the type described above so that a simple structure and an optimized type of power transmission can be achieved. In particular, a transmission is to be created, which is compact and requires little space. It should also be possible in this way to provide multiple pairs of pistons, without the need for complex additional gear.

According to the invention, these objects are achieved by the features of claim 1. Essential in the context of the present invention is the fact that the gear designed with ring gears is located inside the piston raceway, wherein a sufficiently large compression ratio is achieved in that the gears are retracted in the side of the apex, ie have a convex portion. The piston raceway is toroidal, so that the sealing of the movable components relative to the rotor housing and each other with relatively simple means is possible. Preferably outer surfaces of the ring gears form parts of the piston raceway for the pistons, which are firmly connected to the respective other ring gear.

In addition, it is essential to the present invention that the piston drive, which causes the oscillating angular velocity of the pistons, to be formed in a very simple manner as a gear transmission. Through the use of ring gears a large overlap of the teeth and thus a very favorable engagement behavior is achieved, so that the gears are loaded comparatively low and thus can be performed in a relatively small size. It is particularly favorable that the transmission can be arranged in the installation space within the range of movement of the pistons, which minimizes the required installation space.

By the solution according to the invention, reciprocating masses, such as levers or the like, are avoided and a very compact and robust construction is achieved. Thereby, the specific advantages of the present engine concept can be fully exploited, which consist in that the internal combustion engine according to the invention is constructed of very few components, in contrast to the Wankel engine optimum combustion chamber design is possible and the overflow can be generously formed. Overall, an extremely high efficiency can be displayed in this way. The existing engine concept can be optimally used both for internal combustion engines with auto-ignition and for spark-ignition internal combustion engines. In addition, it is possible to display both a two-stroke version and a four-stroke version.

It has turned out to be optimal if two piston pairs are received per rotor housing, so that a total of four combustion chambers are present. Preferably, exactly one working cycle should be carried out in each combustion chamber per revolution. To achieve this, it is preferred if the transmission has a gear ratio of 1: 2. In this way, the above requirements can be optimally fulfilled.

It is particularly advantageous if the ring gears have a major axis and a minor axis perpendicular thereto and if they are symmetrical with respect to the main axis and with respect to the minor axis. This means that the ring gears, like an ellipse, are composed of four mirror-symmetrical quadrants. According to one embodiment, the ring gears are elliptical, resulting in a substantially sinusoidal acceleration and deceleration of the pistons. In this case, the gears with which the ring gears mesh are circular and eccentric.

entsprechen mit $$\mathrm{c}\mathrm{<}\mathrm{a}\mathrm{<}\mathrm{c\surd }\mathrm{2}$$

wie beispielsweise: $${\left({\mathrm{x}}^{\mathrm{2}}\mathrm{+}{\mathrm{y}}^{\mathrm{2}}\right)}^{\mathrm{2}}\mathrm{-}\mathrm{2}\left({\mathrm{x}}^{\mathrm{2}}\mathrm{-}{\mathrm{y}}^{\mathrm{2}}\right)\mathrm{=}1.$$

A particularly advantageous embodiment variant of the invention, however, provides that the ring gears in the region of the secondary vertices, ie the end points of the minor axis, have a convex portion. In this case, the geometric shape of the rolling curve, for example, a Cassinian curve with the equation $${\left({\mathrm{x}}^{\mathrm{2}}\mathrm{+}{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">y</figure-callout>}}^{\mathrm{2}}\right)}^{\mathrm{2}}\mathrm{-}\mathrm{2}{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">c</figure-callout>}}^{\mathrm{2}}\left({\mathrm{x}}^{\mathrm{2}}\mathrm{-}{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">y</figure-callout>}}^{\mathrm{2}}\right)\mathrm{=}{\mathrm{a}}^{\mathrm{4}}\mathrm{-}{\mathrm{<figure-callout\; id="4"\; label="c"\; filenames="imgf0015.png"\; state="\{\{state\}\}">c</figure-callout>}}^{\mathrm{4}}$$

comply with $$\mathrm{c}\mathrm{<}\mathrm{a}\mathrm{<}\mathrm{c\surd }\mathrm{2}$$

like for example: $${\left({\mathrm{x}}^{\mathrm{2}}\mathrm{+}{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">y</figure-callout>}}^{\mathrm{2}}\right)}^{\mathrm{2}}\mathrm{-}\mathrm{2}\left({\mathrm{x}}^{\mathrm{2}}\mathrm{-}{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">y</figure-callout>}}^{\mathrm{2}}\right)\mathrm{=}1.$$

In this way, it is possible to make the angular velocities of the pistons deviating from a sinusoidal movement over time, so that the individual work cycles can have a different length. In this way, it is possible for the pistons to linger longer in the region of top dead center at the beginning of the working cycle, in order to come closer to the ideal of a reciprocating process in order to be able to achieve a higher internal engine efficiency.

A particularly simple construction is achieved in that the ring gears have outer surfaces which form parts of the piston raceway. In this way, separate components can be omitted for power transmission.

Preferably, a plurality of rotor housings are arranged axially next to one another. In this way, it is possible to realize an analog to the multi-cylinder engine of conventional design. In such a case, it is particularly advantageous if the eccentrically mounted gears of several rotors are mounted on a common output shaft.

In order to optimize the combustion process, it is particularly advantageous if the inner wall of the rotor housing is curved in a toroidal shape. This means that the outer wall of the housing is curved in a circular arc or parabolic in longitudinal section. A special case of the toroidal design is a spherical design of the rotor housing.

Radially arranged distribution channels are preferably provided in the toothed wheels for transporting a lubricant. In this way, the oil is conveyed by the centrifugal force in the direction of the piston. In particular, it is favorable in this context if the distribution channels open into a space between piston rings. In this way, the lubricant is guided purposefully to the parts of the piston to be lubricated.

It is particularly favorable if the transmission has non-circular gears whose ratio of the main axis to the minor axis is between 1.2 and 1.9, preferably between 1.3 and 1.6. Together with the width of the piston in the circumferential direction and with the desired compression ratio results in an optimum value for the fluctuation range of the transmission ratio, resulting in the ratio of the main axis to the minor axis.

The occurrence of free inertial forces can be completely prevented that are connected to the eccentrically mounted gears mass balance weights. So can be achieved in the simplest way without additional mass balancing shafts or the like, a completely quiet running of the internal combustion engine according to the invention.

An alternative embodiment of the invention provides an internal combustion engine, which is designed as a rotary piston engine as described above, with at least one rotor housing of circular cross-section in which run several groups of pistons in a rotary motion, wherein a gear with non-circular gears and eccentrically mounted Gears is provided which oscillates the angular velocity of each group of pistons in opposite directions to other groups, so that the angular distance between the individual pistons changes during the circulation. This means, on the one hand, that a group of pistons may comprise three or four pistons, which are each connected to a non-circular gear formed as a ring gear, but also on the other hand, that more than two ring gears may be provided. In this way, the structural density can be increased.

Fig. 1

schematisch eine erfindungsgemäße Brennkraftmaschine im Querschnitt;

Fig. 2

einen Schnitt nach Linie II - II in Fig. 1;

Fig. 3a bis 14c

Diagramme zur Erklärung der Funktion der Erfindung; und

Fig. 15

ein Diagramm das schematisch die Kolbenbewegung darstellt.

The invention will be explained in more detail below with reference to drawings. Show it:

Fig. 1

schematically an internal combustion engine according to the invention in cross section;

Fig. 2

a section along line II - II in Fig. 1 ;

Fig. 3a to 14c

Diagrams for explaining the operation of the invention; and

Fig. 15

a diagram that shows schematically the piston movement.

The internal combustion engine of Fig. 1 consists of a rotor housing 1, which is constructed substantially disc-shaped and has a toroidal cylinder chamber.

Eccentrically to the toroidal cylinder chamber, an output shaft 2 is mounted on bearings 28. Fixed to the output shaft 2, two eccentrically mounted gears 13, 14 are connected, which mesh with non-circular ring gears 3, 4. The two ring gears 3, 4 are connected to pistons 5, 7 and 6, 8, which are arranged movably in the cylinder space. Between each two of the pistons 5, 7 and 6, 8 working spaces 9, 10, 11, 12 are formed. Due to the non-uniform transmission ratio of the gears, which are formed by the internally toothed or eccentrically mounted gears 3 and 4 and 13 and 14, the pistons 5, 6, 7, 8 approach each other alternately during one revolution and in turn move away. As a result, the volume of the working spaces 9, 10, 11, 12 changes cyclically. When in the Fig. 1 illustrated position of the pistons 5, 6, 7, 8, the working spaces 9 and 11 are minimal and the working spaces 10 and 12 maximum.

Laterally in the rotor housing 1, an inlet opening 15 and an outlet opening 16 are provided, via which the gas exchange takes place. Although in the Fig. 1 shown internal combustion engine operates in four-stroke principle, no valves or other control elements are required because the piston 5, 6, 7, 8, the inlet opening 15 and the outlet opening 16 automatically close and release. However, it is alternatively also possible to operate the internal combustion engine according to the invention in a two-stroke process.

The pistons 5, 6, 7, 8 consist of piston bodies with a plurality of piston rings 21, which are constructed in a similar way to conventional piston engines. The pistons 5, 6, 7, 8 are attached via rods 20 and armature 27 to the ring gears.

Spark plugs 17 and 25 serve for ignition, the internal combustion engine operating according to the Otto method. If the internal combustion engine is operated with auto-ignition, an injection nozzle is provided at a comparable location.

The lubrication takes place via a nozzle 30, the oil in the interior 29 of the transmission 3, 4; 13, 14 injects. Radially arranged distribution channels 22 transport the oil further into the region of the pistons 5, 6, 7, 8. The excess oil is discharged via discharge channels 24 on the underside of the internal combustion engine. The cooling of the internal combustion engine via a water jacket 26 outside the piston barrel.

The outer peripheral surfaces of the ring gears 3, 4 represent the inner parts of the piston raceway and are sealed by sealing surfaces 31 against each other and against the housing.

In the Fig. 3a, 3b and 3c to Figs. 14a, 14b and 14c are schematically illustrated the piston positions during a piston revolution. Here are the Fig. 3a to 14a the position, ie angular position of the internal gear 3 and thus the piston 6 and 8, while the Fig. 3c to 14c the position, ie angular position of the internally toothed gear 4 and thus the piston 5 and 7. In the Fig. 3b to 14b the angular positions are shown together and at the same time entered the working cycles, which are assigned to the individual workrooms 9, 10, 11, 12.

Fig. 15 schematically shows the time course of the piston movement and thus the individual work cycles. It is off Fig. 15 It can be seen that the compression stroke and the exhaust stroke are delayed while the intake stroke and the power stroke occur during an accelerated phase of the piston movement.

The invention makes it possible to provide a motor construction which is free of reciprocating masses, requires no valves and the like, so that the number of moving parts is minimal. The internal combustion engine according to the invention is simple, compact and has an extremely high efficiency.

Claims (11)

Internal combustion engine, which is designed as a rotary piston engine, with at least one rotor housing with a circular cross section in which two pairs of pistons (5, 7, 6, 8), in a rotational movement, wherein a transmission (14) with in the inside of Movement path of the pistons (5, 7, 6, 8) arranged, non-circular ring gears (3, 4) having a major axis and a right-angled minor axis, with respect to which they are symmetrical, and each with a pair of pistons (5 , 7; 6, 8) are fixedly connected, and provided with eccentrically mounted gears (13, 14) which oscillates the angular velocity of each pair of pistons (5, 7, 6, 8) counter to the other pair, so that the angular distance between the individual pistons (5, 7; 6, 8) changed during the circulation, characterized in that the inner wall of the rotor housing (1) is toroidally curved and that the ring gears (3, 4) in the region of the side vertex, the si nd the end points of the minor axis, have a convex portion. Internal combustion engine according to claim 1, characterized in that the transmission (14) with non-circular gears (3, 4) and eccentrically mounted gears (13, 14) has a transmission ratio of 1: 2. Internal combustion engine according to one of claims 1 or 2, characterized in that the ring gears (3, 4) have outer surfaces which form parts of the piston raceway. Internal combustion engine according to one of claims 1 to 3, characterized in that a plurality of rotor housing (1) are arranged axially adjacent to each other. Internal combustion engine according to claim 4, characterized in that the eccentrically mounted gears (13, 14) of a plurality of rotors are mounted on a common output shaft. Internal combustion engine according to one of claims 1 to 5, characterized in that in the gear wheels (3, 4) radially arranged distribution channels (22) are provided for transporting a lubricant. Internal combustion engine according to claim 6, characterized in that the distribution channels (22) open into an intermediate space between piston rings (21). Internal combustion engine according to one of claims 1 to 7, characterized in that an open to the housing interior intake passage is provided. Internal combustion engine according to one of claims 1 to 8, characterized in that mass balancing weights are connected to the eccentrically mounted toothed wheels (13, 14). Internal combustion engine according to one of claims 1 to 9, characterized in that the non-circular ring gears (3, 4) have a ratio of the length of the major axis to the minor axis between 1.2 and 1.9, preferably between 1.3 and 1.6 , Internal combustion engine, which is designed as a rotary piston engine, with at least one rotor housing with a circular cross section in which a plurality of groups of pistons (5, 7, 6, 8), in a rotational movement, wherein a transmission (14) with in the inside of Movement path of the pistons (5, 7, 6, 8) arranged, non-circular ring gears (3, 4) having a major axis and a right-angled minor axis, with respect to which they are symmetrical, and each with a pair of pistons (5 , 7; 6, 8) are fixedly connected, and provided with eccentrically mounted gears (13, 14) which oscillates the angular velocity of each pair of pistons (5, 7, 6, 8) counter to the other pair, so that the angular distance between the individual pistons (5, 7; 6, 8) during the revolution changed, characterized in that the inner wall of the rotor housing (1) is curved in a toroidal shape and that the ring gears (3, 4) in the region of the side vertex, d As are the endpoints of the minor axis, have a convex portion.

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