WO1999016998A1

WO1999016998A1 - Internal combustion engine with oscillating rotor

Info

Publication number: WO1999016998A1
Application number: PCT/ES1998/000265
Authority: WO
Inventors: Felix Alvaro Fernandez
Original assignee: Universidad Politecnica De Madrid
Priority date: 1997-09-26
Filing date: 1998-09-25
Publication date: 1999-04-08
Also published as: ES2137122B1; ES2137122A1

Abstract

This new conception of internal combustion engine replaces positively current conventional piston-type engines because at similar service and power performances this new engine provides considerable reduction of weight and cost. The concept of oscillating rotor engine is applicable to substitute any alternating engine having an even number of cylinders and independently any application to which such engine is intended. The thermodynamic transformations and the energetic exchanges obtained with this type of engine are practically similar to those of the piston-type engine of similar power; however, its composition and mechanical operation are very different. The oscillating rotor engine is comprised of a resistant body inside which a rotor provided with blades is housed; a rotor has an oscillating angular motion through an arm-rod-crank mechanism coupled to the powershaft or crankshaft. The blades of the rotor divide the space formed by the body or case into deformable enclosures which act as the cylinders of a conventional alternating engine, with the faces of the blades playing the role of the surfaces of the pistons in an alternating engine.

Description

OSCILLATING ROTOR INTERNAL COMBUSTION MOTOR.

In the current state of internal combustion engine technology, the four-stroke alternative engine is well known, whose applications in propulsion of land, marine and air vehicles, as well as in mechanical or electrical power generation plants and other machinery industrial, they are greatly diversified, and their use is used extensively as a power source in many applications.

The operation of the alternative engine, (also commonly referred to as

"embolism engine"), is based on the work of the active fluid, consisting of air, fuel and waste gases, which evolves cyclically by carrying out the thermodynamic processes of admission, compression, combustion, expansion and exhaust, which take place inside the enclosure which defines the position of the piston inside each cylinder. Due to the acceptable balanced and cyclic regularity that it presents, the most used type of four-stroke alternative engine is the in-line four-cylinder engine, in which the piston displacements are offset by equal values over two turns of the crankshaft . The pistons actuate the respective connecting rods acting on the crankshaft, resulting in the fact that the operating cycles of each cylinder are identical, equally out of phase in half a turn of the crankshaft, and their effects are added at each moment to give a useful torque of the gases.

The most conventional mechanical configuration of said four-stroke engine with four cylinders is "in line"; and it necessarily incorporates a block for four cylinders, four pistons, four connecting rods and a crankshaft with four cranks, as well as the necessary support structure of said components. All these elements are subjected to considerable loads, so they must necessarily have sufficient structural strength and consequently an important weight, which leads to the result that said type of motor has a relatively limited power / weight ratio.

HD On the other hand, rotary engines are also well known in today's technology, of which only the so-called "Wankel engines" have some practical interest. The thermodynamic cycle of a Wankel engine is similar to that of a classic alternative engine, but its mechanical configuration is radically different. In said Wankel engines there is a rotor of suitable lobular geometry, enclosed in a crankcase also appropriately, and among them is the active fluid. The relative movement of the rotor with respect to the crankcase modifies the available volume of the active fluid, so that its thermodynamic cycle is similar to that of the alternative engine. However, the mechanical configuration of the Wankel engine allows for relative improvements in the power / weight ratio, but instead has some drawbacks. The most relevant inconveniences are:

• Important problems to ensure sufficient tightness of the active fluid.

• Crankcase distortion problems due to asymmetry in the peripheral distribution of temperatures on the inner surface of the crankcase.

• Effects of wear of the sealing elements and on the gears that drive the rotor movement.

As a consequence of the presence of such problems, which impose a relatively low reliability and service life, as well as the fact that the development of Wankel engines has not reached the maturity level achieved for alternative engines, said type of engine It has not reached a relevant market penetration.

The Oscillating Rotor Engine, object of the present Patent Registration Application, is conceptually a hybrid mechanical solution between the four-stroke alternative engine, and the Wankel type engine. The concept of this engine seeks to improve the performance of the types mentioned, minimizing the inconvenience of both. Compared to the conventional alternative engine, it has a significantly lower number of components, thus drastically reducing its weight and potential cost. In front of the Wankel engine, it has the advantage of not needing the crown components

IL SHEET Toothed and pinion, which are essential for the Wankel engine epicyclic movement, and in addition, it is exempt from most of the problems associated with the thermal distortion of the crankcase, causing difficulties in resolving the gas tightness, and therefore , originating from wear problems, low reliability, and short service life.

SUBSTITUTE SHEET RULE 26 DESCRIPTION OF INNOVATION.

The invention consists of a four-stroke internal combustion engine, in which there are variable volume enclosures, within which the active fluid operates, similar to how it acts in the cylinders of a conventional four-wheel internal combustion engine times Although this invention is applicable to any even number of enclosures, which function as cylinders in the alternative engine, and since the most extended alternative use engine is that of four cylinders in line, for the purpose of explaining the idea the case of the four-enclosure motor will be specifically described. The mechanical basis of this new motor is exposed through Figure 1, which represents a section through a plane perpendicular to the axis of rotation thereof. the two half-pieces "A" and "B", which internally form two cylindrical sectors, and which are rigidly joined through each other two cylinder head pieces "D" and "C", in which the necessary steps for the intake and exhaust ducts are provided and incorporate the seats of the corresponding valves. These cylinder head pieces "D" and "C" form together with the "A "and" B "a hollow πrido body, whose interior forms two cylindrical sectors coupled to two flat wedges, on which the valves that are represented in imaginary line in the figure.

Concentrically with the axis of the cylindrical bore, the rotor "R" is mounted, whose geometric configuration is that of a circular cylinder provided with two longitudinally arranged equal fins and symmetrically positioned said rotor with its fins conveniently fits inside the cited cylindrical bore , being able to rotate oscillating within the planned cylindrical sector

The presence of the rotor "R" with its fins divides the cylindrical hollow into four enclosures "1", "2", "3", "4", which act as the four cylinders of a conventional alternative engine, since these enclosures they are the ones that will occupy the active motor fluid

ST IÓN R SHEET evolving thermodynamically in the same way as it does in the cylinders of a classic alternative engine. The volumes of these enclosures will vary with the angular position of the rotor at all times, but will always be delimited by the following surfaces: • The inner wall of the semi-crankcase "A" and "B" that form the cylindrical sectors.

• The walls corresponding to the valves of the cylinder head parts "C" and "D".

• The side faces of the two rotor fins.

• The circular part of the cylindrical surface corresponding to the rotor drum. • Flat surfaces that close the anterior and posterior bases of the cylindrical bore. The volumes limited by said surfaces form sealed enclosures that enclose the active fluid while the valves are closed, and their tightness will be guaranteed by the presence of the sliding edge sealing elements "U", and the cylinder head center "V" .

Of all these surfaces the only ones likely to move when the engine is running are the lateral faces of the fins, which are therefore the active surfaces. Figure 2 represents a section through the vertical plane of symmetry of the cylindrical bore, which presents the motor configuration in the direction of the rotor axis "R". As can be seen in said figure 2, the anterior and posterior cylindrical closure bases are solved by means of two flat support pieces "S" and "T", which reinforce the union of the half-pieces "A" and "B" with cylinder head parts "C" and "D" by threaded bolts as shown in the figure. This joint, in addition to closing the cylindrical bore, provides a good structural configuration of the assembly, which makes it susceptible to withstand the high pressures that the active fluid will present in operation.

Said support pieces "S" and "T" also provide housing for the front and rear bearings of the rotor shaft supports, as shown in the figure. Additionally, said "S" and "T" parts extend to accommodate the front and rear bearings of the power shaft or crankshaft of the "E" engine, represented in the

SHEET OF YOUR TIN RE L Figures 1 and 2.

The axis of the rotor "R", at its rear end carries an arm "M", whose axis is positioned perpendicular to the plane of symmetry of the fins, and the end of said arm has a bolt on which articulates a connecting rod "N ". The power shaft or crankshaft "E", which is parallel to the axis of rotation of the rotor "R", is positioned in a convenient situation, and at its rear end it has a crank arm "P", also arranged with its articulating pin with the other end of the connecting rod "N". The set consisting of the arm "M", the connecting rod "N" and the crank "P" completes a classic crank arm-crank mechanism, which produces a full swing angular movement of the rotor "R", for each turn of the crankshaft shaft "E".

The amplitude of the elongation of the angular movement of the rotor (αm), corresponds to half a turn of the crankshaft, and marks the extreme positions of the rotor fins, which are equivalent to the upper and lower dead spots, (PMS and PMI respectively), referents to the comparable alternative engine. Said extreme positions are represented in imaginary line in figure 1.

The angle "αm" is a function of the position of the axis of the crankshaft "E" with respect to the axis of the rotor, of the radii of the arms "M" and "P", and of the length of the connecting rod "N", by which can be selected for a suitable value for said angle, adopting values suitable for the dimensions mentioned.

For fixed values of these dimensions, a given angular position of the rotor "R" corresponds to each angular position of the crankshaft axis "E".

When the angle rotated by the rotor varies, the volumes of the enclosures "1", "2", "3" and "4" vary proportionally, so that the law of variation of said volumes as a function of the angle rotated by the crankshaft , is very similar to the corresponding of the active volumes of the cylinders in an alternative conventional four-cylinder engine. The ratio of maximum volume / minimum volume of each enclosure is identical to the volumetric compression ratio of the comparable alternative engine, and therefore has the same thermodynamic significance as this. Thus, if the motor mechanism is initially positioned, it is assumed

HO If the crankshaft wrist is in the position corresponding to the upper dead center, when the enclosure "1" is at its minimum volume after the escape of its active fluid, the engine operation would be carried out in the following sequence: • During the first half turn of the crankshaft "E", the enclosure "1" performs its admission race, the enclosure "2" performs its compression stroke, the enclosure "3" conducts its expansion stroke, and the enclosure "4 "make your escape run

• During the second half turn of the crankshaft "E", the enclosure "1" performs its compression stroke, the enclosure "2" the expansion, the enclosure "3" the exhaust, and the enclosure "4" the admission

• During the third half turn of the crankshaft "E", the enclosure "1" performs its expansion, the "2" its exhaust, the "3" its intake and the "4" its compression

• During the fourth half turn of the crankshaft "E", the enclosure "1" makes its escape, the "2" its admission, the "3" its compression and the "4" its expansion This sequence is repeated cyclically for successive turns of the crankshaft, and is produced in such a way that the thermodynamic cycle of each enclosure is similar to that of each cylinder of a conventional alternative four-cylinder engine The elementary work of the cycle of an alternative engine cylinder is obtained by the displacement of the force acting on the surface of the plunger, as a result of the pressure of the active fluid at every moment The elementary work of the cycle of an enclosure of the Oscillating Rotor Motor is obtained in an equivalent way, by displacement of the force acting on the active face of the fin of the rotor that limits said enclosure, as a result of the pressure of the active fluid at each instant Thus, said elementary work turns out to be the product of the pressure existing in the enclosure at each i nstante, by the effective area of the fin, and by the elementary arc traveled by the center of the rectangle that forms said effective area In turn, the affective area of the fin is the product of its length (L) by the difference of the head (R) and root (r) radii of the same fin, and the elementary arc traveled through its center is the product of the elementary angle rotated by the rotor by the mean radius between head and root rm = (R + r) / 2 From all this it follows that the elementary work of the cycle of an enclosure for an Engine

HO A DE R of Oscillating Rotor is:

dτ = P * L * (R -r) * (R + r) / 2 * dd

Where (P) is the instantaneous pressure in the enclosure, and (dα) is the elementary angle rotated by the rotor. When (P) acts on the fin's face in the same direction as (d α) the elementary work is positive, (motor work). When it acts in the opposite direction, the elementary work is negative, (hard work).

Considering that the four enclosures act simultaneously but out of phase half a turn of the crankshaft, the elementary work of the gases of the engine assembly will be:

dτ _{Mo (or} = (∑P) * L * (R -r) * (R + r) / 2 * da

Where (Σ P) is the algebraic sum of the pressures of the four enclosures, taking into account its sign according to that of (dα). Consequently, the instantaneous torque of the gases applied to the rotor results:

M _Rotor = (∑P) * L * (R -r) * (R ⁺ r) / 2

Which is, logically, a function of the angle rotated by the rotor (α) at each moment, and whose graphic construction is obtained from the graph of the torque of the gases of an enclosure, added algebraically on itself another three times with half-turn offsets of the crankshaft. Figure 3 shows the directions of the pressures acting in each enclosure, when the enclosure "l" is in its expansion stroke. In the same figure the mechanical scheme of transmission of movement of the rotor to the crankshaft axis (arm "M", connecting rod "N", and crank "P") is represented. The torque of the gases applied to the rotor at each moment is transmitted to the arm "M" of the rotor, driving the connecting rod "N", which acts in turn on the crank arm of the crankshaft, producing the torque resulting from the action

SHEET D IÓN R of the gases on the power axis. The diagram of this pair of gases is very similar to that resulting in a conventional four-cylinder alternative engine at the exit of its crankshaft. Therefore, the cyclic regularity of the oscillating rotor motor will be very similar to that of the alternative motor. However, from the point of view of the maximum loads that the components of the mechanism have to support, there are essential differences between both types of motors, which clearly favor the Oscillating Rotor Motor. The reason for this difference is based on the fact that, in the alternative engine, the maximum load received by the connecting rod corresponding to each cylinder comes from the pressure peak produced by the explosion on the corresponding piston, which acts independently of the rest of the cylinders , and that is transmitted directly to the corresponding crankshaft elbow. This large peak load forces to dimension each connecting rod and each crankshaft elbow with a robustness appropriate to the magnitude of said load. In the oscillating rotor motor the action of peak pressure due to the explosion of an enclosure is transmitted to the active face of the corresponding fin, producing the positive effect of torque to the rotor, but simultaneously the active faces of the fins of the other three enclosures are producing a negative torque effect on the rotor, which by subtracting reduces the maximum load that both the connecting rod and the crankshaft must bear. Consequently, both the connecting rod and the crankshaft will need to have less robustness, and therefore, less weight than in the alternative engine. If it is also taken into account, that the oscillating rotor motor has only one connecting rod and one single crankshaft elbow, compared to four that the alternative motor needs, the weight reduction advantage of the oscillating rotor motor versus the alternative one is undoubtedly justified . The description given in particular for the two-finned rotor motor can be generalized for rotors of any number of fins, simply considering that each fin divides the cylindrical sector in which it moves into two enclosures, so that the total number of enclosures that a particular Oscillating Rotor Motor would have, would be twice the number of fins of its rotor. Since, each enclosure will act in a similar way to how a comparable alternative engine cylinder acts, the described solution would be equally applicable to any type of Oscillating Rotor Motor, according to the number of rotor fins selected in each case. Thus it turns out that, if a single-finned rotor is selected, the corresponding oscillating rotor motor would have two enclosures and would therefore be comparable to an inline two-cylinder alternative engine. If a rotor with two fins were selected, the engine would have four enclosures, and would be comparable to the four-cylinder in-line alternative. For a three-finned rotor, there would be an engine comparable to the six-cylinder in-line alternative. And so on, you could configure any model of Oscillating Rotor Motor, comparable to the alternative engine of any even number of cylinders in line. (For expository purposes the figures present the specific case of a rotor with two fins, which leads to the engine comparable to the four-cylinder in-line alternative).

S 2 SHEET

Claims

CLAIMS:

The invention is declared as new and proprietary, and the exclusive ownership and exploitation of: 1 - Internal Combustion Engine of Oscillating Rotor is claimed, characterized in that it integrates the following essential components.

• A body, which constitutes a rigid housing, whose interior, hollow, is formed by cylindrical sectors, also distributed in the periphery of the hollow and limited by cylinder head shaped parts, where the valves are housed

• A concentric axis oscillating rotor with the housing, whose external geometric shape is that of a circular cylinder provided with longitudinal fins, equally distributed, the number of said fins being equal to the number of cylindrical sectors provided for the hollow interior of the housing This rotor Oscillating has a shaft, which at its exit end carries an arm, provided with a bolt, for articulation of the end of a connecting rod.

• Two flat plates, which close the ends of the inner hollow of the housing, which provide housing to the oscillating rotor shaft, and extend to provide adequate support and positioning to the crankshaft bearing support bearings, motor power output

• A crankshaft axle, supported by the bearings, and provided with a crank arm, which equipped with its corresponding end bolt, provides adequate articulation for the other end of the connecting rod

• A connecting rod whose ends articulate with the respective bolts of the rotor output arm and the crankshaft crank

2 - Internal Swing Rotor Combustion Engine, according to Claim 1, characterized in that the rotor can perform an oscillating angular path, governed by the mechanism of the rotor arm, connecting rod, and crankshaft crank The ends of said angular path define two points of said mechanism 3 - Internal Combustion Engine of Oscillating Rotor, according to claims 1 and 2,

FROM characterized in that each rotor fin divides the cylindrical sector in which it moves into two enclosures, so that the total number of enclosures that the Oscillating Rotor Motor has is twice the number of rotor fins.

4.- Oscillating Rotor Motor Solution according to claims 1 and 2, characterized in that the angle (αm) of elongation of the oscillation of the rotor defines two extreme positions of each fin, and consequently the minimum and maximum volumes of each enclosure when it operates the motor. The ratio of maximum volume / minimum volume of any enclosure is identical to the volumetric compression ratio of the comparable alternative engine, and is calculated by the angle of elongation of the rotor oscillation that is determined based on the geometric dimensions of the component elements of the mechanical transmission, crank-crank, which links the oscillating movement of the rotor with the circular of the crankshaft. 5.-Oscillating Rotor Motor Solution according to claims 1 to 4, characterized in that, the pressure actions acting on the active faces of the rotor fins are added algebraically to produce the resulting torque on the rotor shaft directly , making the presence of a long crankshaft and several elbows unnecessary. 6. Internal Swing Rotor Combustion Engine according to Claims 1 to 5, characterized in that it uses a single connecting rod and a very short and simple crankshaft, which means a reduction in weight in relation to the comparable alternative engine.