HK1077611B - Combustion engine - Google Patents

Description

Combustion engine

The invention relates to a combustion engine comprising a housing with a chamber in which a rotor is arranged provided with a plurality of vanes extending radially to the wall of the chamber and dividing the chamber into a plurality of compartments, wherein each compartment is adapted to perform at least one of the following functions: a) intake and/or compression of gases required for combustion; b) combusting the fuel; c) generating work; and d) discharging the combustion gases, wherein the first pair of vanes is rotatably mounted on a first rotational axis, and wherein the second pair of vanes is rotatably mounted on a second rotational axis, the rotational axes being eccentrically disposed in the chamber.

Such internal combustion engines are known in the art as rotary engines. Rotary engines have many advantages over conventional internal combustion "otto-cycle" engines. By replacing the piston with an epicyclic piston, a rotary engine can in principle suffice with only one chamber. Rotary engines now have an inherent balance configuration whereby the added balance weight common in otto cycle engines can be eliminated. The rotary engine thus has a minimum of components, which increases reliability and reduces production costs.

An example of a rotary engine is described in US patent specification US 6,070,565. In known rotary engines, the blades are coupled in pairs by a yoke that translates about a fixed point. The translational movement of the blade in the rotor is not smooth, since the blade briefly falls into a standstill each time the movement of the yoke is reversed. This creates friction losses which negatively affect the efficiency of the rotary engine. This shaking motion also produces additional vibrations. The maximum rotational speed is also limited by this configuration.

For its purpose, the present invention must provide a rotary engine of the type described in the preamble, which has an improved construction and a higher efficiency. To this end, the rotary engine according to the invention has the feature that the blades in each pair are independently rotatable with respect to each other. Such independently rotating blades have the advantage of always making a smooth movement at a practically constant angular velocity. Rotary engines therefore have lower vibration and are subject to lower acceleration and deceleration forces, which helps to achieve higher efficiency and higher comfort at lower weight.

According to a first preferred embodiment of the combustion engine according to the invention, each of the first pair of blades (5A, 5B) is provided with a protruding portion for mounting on the rotation axis 5. According to a second preferred embodiment of the combustion engine according to the invention, each of the vanes of the second pair (6A, 6B) is provided with a recess with a projection on either side for mounting on the rotation axis 6. Each projection is preferably provided with a bearing mounted about the axis of rotation. This results in a very stable construction even at high rotational speeds.

According to a practical preferred embodiment, the chamber is assembled from three cylinders, the axes of which are substantially parallel to each other. The cross-section of the first portion of the chamber is preferably in the form of a first circle having the first axis of rotation as a centre and a radius approximately equal to the radial dimension of the largest of the associated vanes. The cross-section of the second portion of the chamber is preferably in the form of a second circle centred on the second axis of rotation and having a radius approximately equal to the radial dimension of the largest of the associated vanes. By varying the position of the axis of rotation and the length of the blades, the volume of each compartment, and the ratio between the "intake stroke" compartment and the "power stroke" compartment, can be optimally adjusted. Thus, higher efficiency can be achieved at lower exhaust gas temperatures and lower exhaust gas pressures, which in turn results in lower thermal and acoustic environmental impact.

According to another practical preferred embodiment the radius of the second circle is larger than the radius of the first circle, which results in an optimal performance of the combustion engine.

To complete the design of the actual preferred embodiment, the cross-section of the third part of the chamber is preferably in the form of a third circle located between the first and second circles.

According to a preferred embodiment below, the rotor has a plurality of recesses in order to form a corresponding number of compartments for the combustion of the fuel. Known rotary engines always have a recess on opposite sides. According to the present invention, a plurality of grooves are provided on both sides of the rotor. By varying the number of grooves in use, the engine power can be raised in steps from part load to full load and vice versa. It is generally the case that a larger number of grooves enables more precise control of the engine power. This also results in higher efficiency and cleaner exhaust gases. However, in practice technical possibilities and cost factors will limit the maximum number of grooves. The grooves are arranged in two opposing rows so that two combustions can occur in the engine and two work can be produced per revolution. The form of the recess is preferably cup-shaped or groove-shaped. According to another embodiment, the combustion engine is adapted to inject fuel directly into the recess. By choosing a smaller volume for the grooves, direct injection can be performed efficiently over the entire speed range. The small volume of the recess facilitates achieving the desired air-fuel mixture ratio, whereby the pump losses can be even lower than in a direct injection otto-cycle engine. In a particularly efficient preferred embodiment the combustion engine is adapted to control the engine power by varying the number of grooves injected with fuel.

In a particularly preferred embodiment, the combustion engine operates on the principle of auto-ignition. No ignition mechanism is now required.

The invention will now be discussed in more detail with reference to the drawings of preferred embodiments, in which:

fig. 1 shows a schematic view of a preferred embodiment of a combustion engine according to the invention;

fig. 2 shows a schematic front view of the combustion engine of fig. 1;

FIG. 3A schematically shows a cross-section of the combustion engine of FIG. 1 in a top view with the rotor in a first position;

FIG. 3B schematically shows a section of the combustion engine of FIG. 1 in a top view with the rotor in a second position;

FIG. 3C schematically shows a section of the combustion engine of FIG. 1 in a top view with the rotor in a third position;

FIG. 3D schematically shows a section of the combustion engine of FIG. 1 in a top view with the rotor in a fourth position;

fig. 4 schematically shows a section of a part of the combustion engine of fig. 1 in a perspective view; and

fig. 5 shows a schematic view of a second preferred embodiment of the combustion engine according to the invention without an ignition mechanism.

Fig. 1 shows a schematic view of a preferred embodiment of a combustion engine 1 according to the invention. The combustion engine 1 has a housing 2 in which a space or chamber 3 is located. A rotor 4 is disposed in the chamber 3, and vanes 5A, 5B, 6A, 6B are mounted on the rotor 4. Four vanes divide the chamber into compartments. The housing 2, the chamber 3 and the rotor 4 are substantially cylindrical.

The rotor 4 has a plurality of recesses 7A-H for receiving fuel. These grooves are provided on either side of the rotor and may take different forms. The form adopted is substantially cup-shaped or groove-shaped. An example of a cup shape is a hemisphere or a bowl with an oval cross-section, resembling half an egg. An example of a channel shape is a half cylinder. For purposes of illustration, hemispherical indentations 7A-D are shown in FIG. 1. The number of grooves 7 is equivalent to two or more per side, depending on the engine capacity. For purposes of illustration, it is expected that a number of between four and ten per side will meet the 100cc engine capacity requirement.

The means for metering the fuel are located inside the housing 2. These fuel dosing means preferably comprise a fuel injector 8 adapted for direct injection. An ignition mechanism 9, such as a spark plug, for igniting the fuel is provided adjacent the fuel injector 8. The ignition mechanism 9 is not necessary, since the engine can also operate according to the principle of self-ignition. For purposes of illustration, FIG. 5 shows a second embodiment of a rotary engine according to the present invention, without an ignition mechanism.

Fig. 2 shows the combustion engine 1 in a schematic front view. The combustion engine 1 has a shaft 10 for fastening the engine to the real world. Work produced by the engine may be transmitted by coupling to one of many transmission mechanisms well known in the art. In the preferred embodiment shown, the rotor 4 is coupled to a side member 13 for driving a gear 14 via a drive belt 15 for this purpose.

Fig. 3A-3D show schematic cross sections of the combustion engine 1 with the rotor in a first, second, third and fourth position, respectively. The rotor 4 carries a first pair of blades 5A, 5B rotatable about an axis of rotation 5. The second pair of blades 6A, 6B is rotatable about a second axis of rotation 6. The first axis of rotation 5 and the second axis of rotation 6 are substantially parallel to each other at a mutual distance and extend along a straight line of the chamber 3. Both axes of rotation are eccentrically disposed in the chamber. The two blades 5A, 5B of the first pair are rotatable independently of each other, as are the two blades 6A, 6B of the second pair. This will be further elucidated with reference to fig. 4. Hinges 15A, 15B and 16A, 16B are located on the outer ends of the blades, respectively, which give the blades sufficient freedom to move relative to the rotor 4.

A first important function of the vanes is to divide the chamber 3 into compartments. For this purpose, the blades follow the walls of the chamber 3 during rotation. Each vane is provided with a suitable sealing material both radially and axially on its outer end. Here, some clearance is used between the wall of the chamber and the edge of the seal to allow the rotation of the rotor to proceed unimpeded. An example of a suitable sealing material is a ceramic material. The second important function of the blade is power transmission. In this respect, the first pair of blades 5A, 5B is also referred to as compression blades and the second pair of blades 6A, 6B is referred to as working blades.

The chamber 3 is substantially non-circular in cross-section. The chamber 3 is assembled from three eccentric cylinders partially overlapping each other. The cross section consists of three eccentric circles. In fig. 3A-3D, the left part of the chamber 3 is in the form of (a part of) a circle L centered on the axis 5 and having a radius approximately equal to the radial dimension of the vanes 5A and 5B. The right part of the chamber 3 is in the form of (a part of) a circle R centred on the axis 6 and having a radius approximately equal to the radial dimension of the vanes 6A and 6B. The central part of the chamber 3 is in the form of (a part of) a circle M. The volume ratio of the relevant cylinders L and R determines the performance of the combustion engine. These volumes can be adjusted by selecting the position of the axes 5 and 6 and by selecting the radial dimensions of the vanes. The optimum volume ratio is a function of the compression ratio. For example, at a compression ratio of 1: 18, which is typical for diesel engines, the volume ratio is approximately volume_LVolume of_R＝1∶3。

The rotor 4 is substantially circular in cross-section. The diameter here is substantially equal to the diameter of the circle forming the central part M, in this embodiment the smallest diameter of the chamber 3.

An air inlet 11 and a combustion gas outlet 12 are located on the lower side of the chamber.

During rotation, the chamber is divided into compartments, the volume of which changes. The number of compartments may vary, being three or four, depending on the position of the rotor. In this way, the functions of the intake stroke, compression stroke, power stroke and exhaust stroke of the combustion engine, which will be elucidated hereinafter, are achieved.

The combustion engine according to the invention operates as follows.

Fig. 3A shows the rotor in a first position. The chamber is now divided into three compartments, 3A-3C respectively. In compartment 3A, air is drawn in through inlet 11. The air present in compartment 3B is compressed to the maximum in the recess 7A and in all compartments located in the same row. The fuel injector 8 now injects fuel into one or more of the recesses (depending on the power required) to produce a combustible mixture in each injected recess. If the fuel is gasoline, this is preferably done at a ratio of 1 part fuel to 14 parts air. The mixture is exploded by a spark plug 9. In compartment 3C, expansion takes place after a burst of prior combustion and work is produced.

Fig. 3B shows the rotor 4 in a second position, in which the rotor is rotated approximately 45 degrees in the clockwise direction. The chamber is still divided into three compartments, now referred to as 3A, 3C and 3D respectively. The volume of compartment 3A is further increased by the intake of air through inlet 11. After combustion, compartment 3B of figure 3A becomes compartment 3C which expands thereby and produces work. The volume of compartment 3D is further reduced during the discharge of the combustion gases present therein through the discharge opening 12.

Fig. 3C shows the rotor 4 in a third position, in which the rotor continues to rotate about 45 degrees again in the clockwise direction. The chamber is now divided into four compartments, 3A-3D respectively. In compartment 3A, fresh air is drawn in through inlet 11. The air present in compartment 3B is compressed. In compartment 3C, expansion still occurs after combustion and work is produced. The combustion gases located in compartment 3D continue to be discharged through the discharge opening 12.

Fig. 3D shows the rotor 4 in a fourth position, in which the rotor continues to rotate about 45 degrees again in the clockwise direction. The chamber is still divided into four compartments, 3A-3D respectively. The volume of compartment 3A is further increased by the intake of air through inlet 11. The air present in compartment 3B is further compressed. In compartment 3C, expansion still occurs after combustion and work is still produced. The last combustion gases left in compartment 3D are discharged through discharge opening 12.

Fig. 4 shows a schematic cross section of a part of the combustion engine of fig. 1 in a side view. The rotation axes 5 and 6 on which the blades 5A, 5B and 6A, 6B are mounted pass through the shaft 10. The first pair of blades (5A, 5B) each have a substantially central projection for mounting on the axis of rotation 5. For illustration, the protruding portion 25A of the blade 5A is shown in FIG. 4. The blade 5B is provided with a similar projecting portion. Each of the second pair of blades (6A, 6B) is provided with a substantially central recess provided with a protruding portion on both sides for mounting on the rotation axis 6. Only the protruding portions 26A and 26B of the blade 6A are shown in fig. 4 with a groove in between. The blade 6B has a similar configuration. All the projections are provided with suitable bearings, such as slide bearings.

To summarize, the volume of the compartments 3A-3D varies periodically with the rotation of the rotor 4. These volume changes are similar to the volume changes of the piston in known otto-cycle engines and have the same function of periodically effecting the intake stroke, the compression stroke, the power stroke and the exhaust stroke. In the combustion engine according to the invention, two combustions occur per revolution and two work are produced per revolution. The preparatory work for the fuel combustion to take place again, i.e. the intake and compression of the gases required, occurs substantially in the left part (L) of the chamber 3, while the most recent combustion is handled by power transmission and combustion gas discharge in the right part (R).

In the rotary engine according to the present invention, only air is sucked. The air drawn in is first compressed to the maximum extent. Fuel is then injected into one or more recesses/compartments 7 respectively. The grooves have a relatively small volume, so that filling each groove with fuel and allowing the resulting mixture to burn completely requires a relatively short time. The individual grooves are almost completely separated from each other during spraying. This is achieved by the form of the groove and the position of the groove at the time of spraying. At the time of injection, the compressed air is heated to meet the conditions required for auto-ignition, so that the use (and thus the absence) of an ignition mechanism is no longer necessary. Thus, by omitting the ignition mechanism 9 in all the figures, a second preferred embodiment of the rotary engine is obtained. For illustration, fig. 5 shows a schematic view of this second preferred embodiment of the combustion engine according to the invention without an ignition mechanism. Fig. 5 is otherwise identical to fig. 1. It should be noted that an additional fuel injector 8 may be provided instead of the ignition mechanism 9 in order to achieve an optimal fuel distribution in each recess and to achieve a more rapid and cleaner combustion.

The performance of the rotary engine according to the invention shows a significant improvement over the known four-stroke otto-cycle engine, as shown in the table below. The following ratios apply to equal powers. Doubling the rotational speed of a rotary engine also doubles the cylinder capacity, volume, weight and production costs required for an otto-cycle engine to produce the same power.

	Rotary engine	Otto cycle engine
			Power plant	1	1
Rotational speed	1..2	1
			Cylinder capacity	1	4...8
Volume of	1	4...8
			Weight (D)	1	4...8
Efficiency of	2	1
			Raw materialProduction cost	1	4...8

It should be noted that for purposes of illustration, the rotary engine is a gasoline engine. However, the rotary engine according to the invention is also suitable for diesel fuel. Once in use, it is even possible to fill the different types of fuel alternately (as long as the sump is as empty as possible before filling) without structural modifications. Rotary engines are also suitable for use in a variety of vehicles. Some examples include automobiles, motorcycles, mopeds and scooters, as well as airplanes and boats.

Thus, the invention is not limited to the preferred embodiments shown, but extends substantially to any embodiment that falls within the scope of the appended claims, when viewed in light of the foregoing description and accompanying drawings.

Claims (16)

1. A combustion engine (1) comprising a casing (2) with a chamber (3) in which a rotor (4) provided with a plurality of vanes (5A, 5B, 6A, 6B) is arranged, the vanes (5A, 5B, 6A, 6B) extending radially to the wall of the chamber (3) and dividing the chamber into a plurality of compartments (3A, 3B, 3C, 3D), wherein each compartment is adapted to perform at least one of the following functions:

a) intake and/or compression of gases required for combustion;

b) combusting the fuel;

c) generating work; and

d) the combustion gas is discharged out of the furnace,

wherein a first pair of blades (5A, 5B) is rotatably mounted on a first axis of rotation (5) and wherein a second pair of blades (6A, 6B) is rotatably mounted on a second axis of rotation (6) which axes of rotation are eccentrically disposed in the chamber (3), characterized in that the blades (5A, 5B; 6A, 6B) of each pair are independently rotatable with respect to each other.

2. Combustion engine according to claim 1, wherein each of the first pair of blades (5A, 5B) is provided with a protruding portion for mounting on the rotation axis (5).

3. Combustion engine according to claim 1, wherein each of the second pair of blades (6A, 6B) is provided with a recess with a protruding part on either side for mounting on the rotation axis (6).

4. A combustion engine according to claim 2 or 3, wherein each projection is provided with a bearing mounted about the axis of rotation.

5. Combustion engine according to claim 1, wherein the chamber is assembled from three cylinders which partially overlap each other and have axes substantially parallel to each other.

6. Combustion engine according to claim 5, wherein the cross section of the first part of the chamber is in the form of a first circle (L) centred on the first axis of rotation (5) and having a radius approximately equal to the radial dimension of the largest of the associated blades (5A, 5B).

7. Combustion engine according to claim 5, wherein the cross section of the second part of the chamber is in the form of a second circle (R) centred on the second axis of rotation (6) and having a radius approximately equal to the radial dimension of the largest of the associated blades (6A, 6B).

8. Combustion engine according to claim 5, wherein the cross section of the first part of the chamber is in the form of a first circle (L) centred on the first axis of rotation (5) and having a radius approximately equal to the radial dimension of the largest of the associated blades (5A, 5B), wherein the cross section of the second part of the chamber is in the form of a second circle (R) centred on the second axis of rotation (6) and having a radius approximately equal to the radial dimension of the largest of the associated blades (6A, 6B), and wherein the radius of the second circle (R) is larger than the radius of the first circle (L).

9. Combustion engine according to claim 5, wherein the cross-section of the third part of the chamber is in the form of a third circle (M).

10. Combustion engine according to claim 1, wherein the rotor has a plurality of grooves in order to form a corresponding number of compartments for the combustion of the fuel, characterised in that a plurality of grooves (7A, 7B, 7C, 7D; 7E, 7F, 7G, 7H) are provided on both sides of the rotor (4).

11. Combustion engine according to claim 10, wherein the recess is in the form of a cup.

12. The combustion engine of claim 10, wherein the grooves are in the form of channels.

13. Combustion engine as claimed in claim 10, wherein the combustion engine is adapted for direct injection of fuel into the recess.

14. Combustion engine as claimed in claim 13, wherein the combustion engine is adapted to control the engine power by varying the number of grooves injected with fuel.

15. Combustion engine according to claim 10, wherein the combustion engine is adapted to enable self-ignition of the fuel without the use of an ignition mechanism.

16. The combustion engine of claim 15, wherein the combustion engine does not include an ignition mechanism for the fuel.