A HIGH EFFICIENCY ROTARY INTERNAL COMBUSTION ENGINE

FIELD OF THE INVENTION

The present invention relates to an internal combustion engine. More particularly it relates to a positive displacement rotary engine, different from set of reciprocating cylinders arranged radially. The efficiency of the engine is increased substantially and it enables the user to exercise a choice for engine capacity selection, while driving the vehicle.

PRIOR ART AND ITS DRAWBACKS Reciprocating internal combustion engines have existed since almost a century. There are two types - Spark ignition and compression ignition. Spark ignition is for the petrol or gas based engines. Compression ignition is for diesel engines.

Rotary Internal combustion engines like Wankel Engine and Turbojet Aircraft engine are also developed long back and used for over 30 years. Wankel engine employees a triangular shaped object, which rotates inside a chamber. Variable shape rotors are known from the prior art, as an example of which was provided by Werner in (U.S. Pat. No. 716,970). Another type of engine was disclosed by Wankel, who established a rotary engine with a fixed shape rotor and epitrochoidal shape stator.

A contemporary embodiment of the cycling machine utilizing Werner's principle is described in U.S. Pat. No. 6,164,263, in which roller carriages pivotally connected to the ends of the blades create a lateral support for the rotor and simultaneously provide a cam surface for the rotor shape deformation. In this device, an additional variation of the volume between the blades, side covers and a stator is achievable due to variation in relative positions of the carriages and blades.

German Patent No. 1 ,295,569, provided a rotary internal combustion engine, in which two pistons are provided, which are connected to the shaft by means of two diametrically opposite arms fixedly connected to the shaft.

Other engines are represented by concepts proposed in the prior art and include a pressure energy converter, rotary engine or compressor as in U.S. Pat. Nos. 4,068,985,

3,996,899; a rotary disk engine as in the U.S. Pat. No. 5,404,850; a rotary planetary motion engine as in U.S. Pat. No. 5,399,078; a rotary detonation engine as in the U.S.

Pat. No. 4,741 ,154; a rotary combustion engine as in DE patent 2,448,828, U.S. Pat. Nos. 3,933,131 , 4,548,171, 5,036,809; the Wankel type engine as in the U.S. Pat. Nos. 3,228,183, 4,308,002, 5,305,721 , and a continuous combustion engine as in the U.S. Pat. No. 3,996,899. Most rotary engines, and particularly the Wankel and those described in the U.S. Pat. Nos. 3,442,257, 3,614,277, 4,144,866, 4,434,757, DE Patent No. 3,027,208 are based on the principle of volume variation between a curve and a moving cord of fixed length as a single sliding piston.

a. Prior Art - Reciprocating Engines

1. At the time of ignition piston is nearly at TDC and the crank makes a very small angle with the force of piston, hence a very small vector component of force on piston actually causes crank rotation.

2. The combined effect of varying force and varying angle cause loss of force vectors in reaction forces and deliver less average usable force for crank movement.

3. The total force required for direction reversal of the 2 objects namely piston and connecting rod are significant.

4. Vibrations are significant d,ue to high total weight of reciprocating pistons and connecting rods and also due to force acting on different points of crank shaft in a multi-cylinder engine.

b. Prior Art - Rotary Engines

Wankel engine is rotary and seemingly works on positive displacement due to a closed combustion chamber. But Wankel engines are known to have low fuel efficiency. The gas expansion conceded by near triangular rotor or Reuleaux triangle which converts the force into mechanical movement is neither linear not circular.

Due to design of the Wankel engine, the Rotor face is nearly parallel to its instantaneous direction of motion at the time of firing. The actual transfer of force to shaft takes place at

rotor-shaft contact point in nearly opposite direction. Hence though positive displacement and rotary, Wankel engine has low fuel efficiency.

Aircraft turbojet engines are not positive displacement engines. Though they produce very high power, work at very high speeds, they also consume a very high fuel. The Aircraft movement is not based on a drive, but on jet propulsion hence they are entirely different that automotive IC engines.

In yet another prior art that, a Rand Cam Engine, the said engine comprises of a disc- shaped rotor and driveshaft which turn, the housing or stator which remains stationary.

Up to 12 vanes mounted parallel to the shaft slide up and down along the outside of the rotor as they follow a track along the inside of the stator housing. Combustion chambers form between the rotor, stator walls and vanes, and their volumes change as the vanes move during rotation. The combustion chambers are also balanced around the rotor, plus the rotor acts as a flywheel to smooth out power imbalances and eliminate destructive harmonics. The difference between the present invention this rand cam engine is summarised below in a tabular form:

It is the object of the invention to deliver expansion force constantly at 90 degrees to the crank.

It is yet another object of the present invention to have a positive displacement internal combustion.

It is yet another object of the present invention to be able to fire part of engine cubic capacity without any vibrations.

DESCRIPTION OF THE INVENTION

The present invention is now explained with the help of figures. Fig 1 : Reciprocating Engine in prior art. Fig 2: Wankel engine in prior art. Fig 3: Rand Cam engine in prior art

Fig 4: Cross sectional top and front view of the present invention.

In the preferred embodiments of the present invention, the following are employed: i. An Engine housing (1) ii. A Rotor (2) similar in function to a piston of reciprocating engine which converts gas expansion to mechanical power. It has expansion face (9) iii. Sweep blades (3) for offering resistance to gas expansion in one direction causing rotor to rotate in an opposite direction. iv. Together the rotor and the sweep blade form a logical expanding combustion chamber (4) v. A Timing device (5) for inlet valve, spark plug and injectors. vi. A shaft (6) which is connected to the rotor by arms, flange or disc which become crank (7). vii. An air compressor and compressed air tank (8) viii. Like reciprocating engine, other parts like valves, spark plugs, fuel injectors, bearings, gaskets etc are necessary for this engine.

This invention is being illustrated in the accompanying drawings.

Principle of this invention:

In the present invention the force of gas expansion is received and converted into mechanical movement by a rotor (2) which is equivalent to a piston and concedes space to gas for expansion. It is a rotary engine but not a turbine. It is a positive displacement rotary engine but different from set of reciprocating cylinders arranged radially which was a "fixed crank" variation of the Slider Crank Chain mechanism.

For a positive displacement system and to get force at 90 degrees to crank, piston must rotate with crank. For piston rotation following technical requirements need to be fulfilled:

1. To be able to move piston, combustion chamber has to be fixed constrained so that expanding gas pushes crank/piston away from the combustion chamber in a particular direction.

2. The combustion chamber and piston have to come close again after every firing to enable firing it again. Therefore in a constant speed operation, combustion chamber has to accelerate faster than piston.

3. Fora rotary model combustion chamber cannot remain completely fixed because it will come in way of piston during rotation

The solution to the above limitations is to bring a constrained combustion chamber momentarily just behind the piston in every rotation. But there are other issues attached to it. 1. The piston and the combustion chamber brought behind it must make a closed system for a positive displacement.

2. They have to remain closed for through full displacement of the piston. If a constrained closed chamber is brought over the piston face and fired, the piston will move away, but it will open the system and gas will escape from the gap created.

It is the object of the present invention to solve this problem by creating logical expanding combustion chambers on a rotor with the help of a sweep blade.

CONSTRUCTION AND WORKING:

The engine housing (1) houses the rotor (2) and most of other parts. The rotor has a cavity. The sweep blade (3) enters the cavity and creates a partition. Once inside the cavity, the sweep blade is fixed while the rotor moves. Right hand side of the partition becomes a logical expanding combustion chamber (4) formed between the expansion face of rotor (2) and the sweep blade (3). It is called logical because it is created by dividing empty space. The spark plug, inlet valve and injectors etc are fixed on the housing just right to the sweep blade. There is no exhaust valve required.

The combustion chamber thus formed can take in air and fuel through an inlet valve and injector and expand on firing. As the sweep blade is fixed, the rotor is forced to move only in one direction to allow expansion of gas. Since the rotor is mounted on the shaft (6) through a flange or arms which make the crank (7), gas power is effectively converted into mechanical movement.

As the rotor turns, the blade is withdrawn at end of cavity. The blade is controlled by a timing device (a cam) matching cavity profile and a spring. The expanded gas remains inside the cavity. When the sweep blade enters the cavity in next rotation, the right hand side becomes the expanding combustion chamber and the left hand side becomes the contracting exhaust chamber. Gases which were inside the chamber after the expansion are pushed out from an open exhaust port as the blade sweeps through the cavity. The open exhaust port is on the left of the blade.

It is the object of the invention to achieve the compression of air externally.

Compression of air is done by a compressor outside the combustion chamber. It is an internal combustion engine but not internal compression engine. This is therefore suitable for spark ignition only. Compression ignition may be devised in future based on this invention.

When inlet valve opens, compressed air is fed into chamber from a compressed air tank which is filled by an air compressor. Any type of air compressor or turbo charger can be

used. The engine may even work without compressed air as there is no need for a punch. The reason is that as there is no resistance offered to the rotor due to factors like reciprocation of piston or compression of gas. Power delivery can be smooth.

Operation of sweep blade (3) is through a spring and timing device. It is spring loaded like a valve of reciprocating engine, spring force pushing it towards rotor cavity and timing device profile restricting it. It enters and exits rotor cavity as the rotor turns.

The engine will also require cooling system which can be done with established methods or by circulating water through a water jacket inside the rotor and housing.

Utilisation of expansion force

The combustion chamber (4) is completely closed from all sides. Hence there is a positive displacement of rotor since gas cannot expand without moving rotor. At the same time, the expansion force on the rotor face (9) is always perpendicular i.e. at 90 degrees to the crank. There is no intermediate part like a connecting rod therefore expansion force F1 is directly resolved as Fp which is same as F1 as included angle between F1 and Fp is zero degrees. Since expansion force F1 and Fp are same vectors, it results in high efficiency.

The engine can have zero idling RPM in a multi-cavity rotor engine with such an arrangement that one combustion chamber is always in a position for firing. Since it does not compress the air inside the combustion chamber, compressed air and fuel mixture is released into combustion chamber and sparked. Since there is no internal resistance to rotor, it can start producing power without initial cranking and momentum requirement, only compressed air has to be fed for starting engine. This also increases fuel efficiency.

Comparison of power delivery to other engines

In reciprocating engine only a component (Fp) of the force causes the actual rotation. Even at momentary 90 degrees crank position, some force component is lost as connecting rod is not at 90 degrees to piston.

In Wankel engine, much of the expansion force (F1) acting on expansion face of moving combustion zone acts normally to the rotor surface (Fr) and produces a reaction force at the opposite vertex on the triangular rotor. A small component (Fp) actually produces motion.

In this invention, there is no component of expansion force (F1) on rotor which causes a reaction force as technically the rotor does not contact any surface / link offering reaction force in opposite direction. Hence it transfers almost 100% of the force (F1) on expansion face on rotor to the crank for rotation.

The gas turbines also fulfil some objectives of this invention. They offer a force at constantly 90 degrees to the radius and are scalable in terms of capacity / power. However, they are not Internal Combustion and positive displacement engines.

There can be one or more such cavities on one rotor in the engine. Since sweep blades, inlet valves, fuel injectors, spark plugs, exhaust ports are on the engine housing or a non-moving part, their number is independent of the number of cavities on the rotor. For example, there can be 3 sets of sweeping blades, inlet valves, spark plugs and exhaust and 5 cavities. The configuration is done by designer, but their operation can be determined by the user. A 3 blades, 5 cavity rotor engine can be fired from 1 to 15 instances per rotation. The number of firing will determine the power generated. Power will also be determined by the fuel-air mixture using throttle control. Any one or all chambers in any configuration can be fired at any or all the blades using a control mechanism.

Withdrawal Mechanism:

The blade is guided by the timing device in such a way that it is constrained/restricted only in the direction of the cavity and a spring maintains a contact between the blade and the timing device. A withdrawal mechanism similar to a cam selects engagement or disengagement of blade with timing device. Position of withdrawal mechanism determines number of blades in operation and also operation of valves, injectors of respective blades. Thus user gets a control on power produced by the engine by controlling the fired CC. Such mechanism can be used to reduce power produced under

low load conditions or idling or slow traffic movement using a high reduction ratio in gear box.

It is the object of the present invention to provide a withdrawal mechanism to reduce the power produced under situations like low load conditions etc.

Exhaust port has to be always open but gases will not escape from combustion space before displacing rotor. It is not similar to a 2-stroke engine where fresh fuel-air mixture and exhaust gases can get mixed up. Closing the exhaust port in this engine gives a strong self brake to engine due to air lock. It is just like a normal reciprocating engine which will stop if the exhaust pipe is firmly closed. Since exhaust port is always open, there is option to use it as a brake by partial closing.

Depth, width and Length of rotor cavity will determine the initial volume and expansion available inside the engine. A longer cavity will ensure complete combustion.

Modifications and variations

1. Rotor cavity can be created from any side and sweep blade can operate from that side. 2. There can be multiple rotors on one engine shaft. Thus this is a highly scalable design where rotor units can be fired independently without affecting engine balancing.

3. Timing can be mechanical, electrical or electronic. Sweep blade can be substituted with a different shape for example L-shape, but doing the same function of creating a combustion chamber by dividing space.

4. This engine is suitable for spark ignition at present but compression ignition engine can be developed based on same principles.

STATEMENT OF THE INVENTION:

An improved internal combustion engine comprises an engine housing, an air compressor and a compressed air tank, valves, spark plugs, fuel injectors, bearings, gaskets characterized in that a rotor being housed in the said engine housing, the said rotor having at least one cavity with an expansion face, at least one sweep

blade being mounted on the said engine housing, that enters the cavity of the said rotor to create a partition, the said cavity of the rotor and the said sweep blade forming one or plurality of combustion chambers, a timing device to control the operation of the sweep blades, inlet valve, spark plug and injectors, a shaft being connected to the rotor by means of arms to function as a crank thereby creating a

High Efficiency Internal Combustion Engine.

The said sweep blade is spring loaded like a valve of reciprocating engine, the said spring force pushing it into the rotor cavity as the rotor turns. The said expansion face of rotor is the face where the force of gas expansion acts to produce motion of the said rotor.

An expansion face of the said rotor is a face on the cavity of the rotor, which is machined, in a radial plane.

The no of said blades is less than the no of cavities and no of cavities on the rotor depends upon the engine cubic capacity requirement and a disc is connected to the rotor to function as a crank in place of arms.

Further, a control mechanism similar to a cam engages with blade and allows it to be withdrawn from said cavity and disengaged from the said timing device, holding said blade from cavity so that the said blade no longer enters the said cavity, the position of withdrawal mechanism deciding number of said blades withdrawn and also operation of fuel injectors, inlet valves for the respective blades.

Said Cavity on rotor is on Internal Diameter or on Outer Diameter or on face. The same construction of a rotorwith cavity and a blade, valves housed in a housing can be used for construction of a hydraulic pump, compressor, hydraulic drive or a pneumatic drive

Although a specific embodiment of the invention has been described herein in detail, this has been done solely for the purpose of illustrating the invention in several of its aspects, and it is to be understood that the foregoing description does not limit the scope of the invention. It is contemplated that various substitutions, alterations and/or modifications to the embodiment of the invention disclosed herein, including but not limited to those implementation options specifically noted herein, may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims.

ADVANTAGES

1. Delivery of 100% expansion force due to burning of fuel at constant 90 degrees to the crankshaft 2. Eliminates reaction forces.

Sr Ensure positive displacement of load (like a piston) for maximum fuel efficiency.

4. Enables running engine using only part of its cubic capacity to run at high RPM but low power and fuel consumption.

5. Manufacturing of such engine is highly economical. 6. It is highly scalable design.

7. Very High fuel efficiency.

8. Operation is vibration free as there are no reciprocating parts. Sweep valves are reciprocating but have very small weight. All forces of expansion act in tangential direction and in a single plane even in a multi-cavity design. 9. Idling RPM is very low or zero, virtually no power is required for idling.

10. It converts fluid pressure to motion and motion input to fluid displacement with equal efficiency due to a radial face inside the cavity and positive displacement.