Title of Invention

INTERLACED DELTA ENGINE

Abstract

An interlaced delta engine comprising of a main shaft, three secondary crankshafts all rotating in the same direction, the three sec. Shafts form vertices of an equilateral triangle, the main shaft being located at centre of said triangle, each secondary crank shaft having two crank pins which lie on the plane perpendicular to respective crank shaft, three cylinders being placed between the crank shafts such that this apparently form the sides of the triangle, each cylinder has two pistons reciprocating within it and the space enclosed between the two pistons forming the combustion chamber, each piston being connected to corresponding crank shaft by means of a connecting rod,

Full Text

FORM 2 THE PATNENT ACT, 1970 (39 of 1970) Complete Specification [See section 10] " INTERLACED DELTA ENGINE " 2. (a) MR. PRASAD JAYANT CHODANKAR (b) 183/C, Shelar Bhuvau, Veer Savarkar Marg, Mahim, Mumbai-400 016. Maharashtra, India. (c) INDIAN. The following specification particularly described the nature of invention and the manner in which it is to be performed. ORIGINAL 865/MUM/2004 GRANTED 21-2-2005 TITLE:- "INTERLACED DELTA ENGINE" FIELD OF THE INVENTION This invention is in the field of internal combustion engines. It is particularly concerned with the way an engine is configured such that it provides a very flat, low profile and compact design, enabling it to be mounted onto a shaft or pulley of any machine or directly into the wheel of a vehicle. It primarily works on the two stroke engine cycle and can be adapted as a compression or spark ignited type. BACKGROUND OF THE INVENTION The engine is basically formed by combining together three opposed piston engines in a unique way. An opposed piston engine consists of a cylinder, housing two pistons having opposite throws, each of which is connected to a crankshaft placed at either end of the cylinder. The crankshafts are connected to each other with the aid of a gear train or a chain and sprocket drive. The combustion chamber is formed by the space enclosed between the two pistons. There are two sets of ports (inlet and exhaust) placed circumferentially around and at opposite ends of the cylinder. One of the pistons controls the opening of the inlet port while the other one controls the opening of the exhaust port. This arrangement has some distinct advantages over a single piston and cylinder setup, which are listed below. * Since the inlet and exhaust ports are at either ends of the cylinder, the flow of gases is always in one direction (uniflow) which leads to a very efficient means of scavenging. * There is no requirement of a separate cylinder head and valve mechanism which results in a simple design involving very less moving parts. * The relative piston velocity is double for a given crank and piston speed. * A means of having unsymmetrical port timing can be obtained (i.e. the exhaust port can be made to open much before the inlet port opens and made to close at nearly the same time the inlet port closes). This is done by providing a slight angular offset between the two crankshafts, 5 which is termed as crank lead), because of which the two pistons do not come to the end of their stroke at the same time. * Since the inlet and exhaust ports are at either ends of the cylinder and don't interfere with each other, they can be made to lie around the entire circumference of the cylinder which leads to an increased port capacity. However an opposed piston configuration has certain drawbacks which are as follows. * The use of the crankcase as a scavenging pump cannot be made. This is because the crankcase can supply a volume of charge which is equivalent to that displaced by a single piston, however the volume of charge required in the cylinder is that displaced by two pistons. Because of this an additional (and external) pump is required which leads to more parts being used in the engine resulting in a bulkier design. * The engine requires two crankshafts per cylinder rather than one which again results in a bulky design. In some engine types the use of just one crankshaft has been made, but in these types of opposed piston engines either one of (or in some types both) the piston/s are made to connect to the crankshaft by means of a lever mechanism. This again leads to a complex design and also involves large reciprocating components which tend to reduce the maximum speed at which these engines can be run. This makes the use of a single crankshaft rather impractical. * If two crankshafts are used, a means of connecting the output from the crankshafts to each other is also required which is generally done by providing a gear train or a chain and sprocket drive. This again results in more engine parts and a larger engine. If a third crankshaft is added such that the three crankshafts are placed at the vertices of an equilateral triangle then we can add two more cylinders such that the axes of these cylinders will form the three sides of the triangle. This configuration is what is called as a "delta configuration'. As we can see, this configuration will be more efficient that a single cylinder opposed piston engine because it has three cylinders and three crankshafts rather that one cylinder and two crankshafts. The three cylinders have to be made to fire at a regular interval from each other (that is 360°/3 = 120°) which will result in a very uniform and well balanced engine. Now if we consider just one of the cylinder the crank lead 5 is 180°-120° = 60°. In practice the crank lead is generally limited to a maximum of about 25°. Any further increase in the lead will result in an improper two stroke cycle resulting in a very inefficient engine. This has proven as a major setback for the delta configuration and explains the reason why the advantages of this kind of configuration have not been exploited. In a particular design, one of the crankshaft is made to rotate in a direction opposite to the other two crankshafts. This gives the required result but require multiple banks of such cylinders. It cannot be used for just one bank of cylinders because of the unbalanced firing order that is produced. It also requires additional gears to change the direction of rotation of the third crankshaft. In another design the combustion chamber is formed by joining two cylinders that are inclined at 60° to each other. The resultant configuration is a hexagon having three crankshafts at aitemate comers and six cylinders forming the sides of the hexagon. In some other designs the three crankshafts have been replaced altogether by just one crankshaft in the center of the triangle, but here the pistons are connected to the crankshaft through a system of levers resulting in rather heavy reciprocating masses. The said invention makes use of all the advantages in an opposed piston engine and eliminates the drawbacks of the delta configuration, the details of which are given below. SUMMARY OF THE INVENTION The said invention is an internal combustion engine working on a two stroke engine cycle (compression or spark ignited type). The invention comprises of a unique way of configuring three crankshafts and three cylinders (one cylinder in between two crankshafts) such that they form an interlaced triangle. Each of the cylinders has two pistons reciprocating within it at either ends. The space enclosed between the two pistons forms the combustion chamber. The three crankshafts rotate in the same direction and at a phase difference of 120° to each other. They are apparently arranged such that they form the vertices of an equilateral triangle. The main shaft is located at the center of the said triangle and power is transmitted to the main shaft from the three crankshafts with the aid of gears. The three cylinders are placed between the crankshafts such that they apparently form the sides of the triangle and are made to fire at regular intervals that are 120° apart from each other for one complete revolution of the crankshafts. Each crankshaft has two crankpins each placed along different planes of rotation and are positioned at an angle (180 -120 - 8 + p)° apart from each other, where 8 is the crank lead required between the two crankshafts in a particular cylinder and p is a function of 'the distance between two crankshafts' and 'the distance between the planes along which the two crankpins (of the same crankshaft) rotate". The three crankshafts are made to incline at an angle a to the main shaft. Here again a is a function of 'the distance between two crankshafts' and 'the distance between the planes along which the two crankpins (of the same crankshaft) rotate". If we consider any particular cylinder, it will have a crankshaft at one end and a second crankshaft at the other end (each of the crankshafts having two crankpins). The angle a enables the cylinders to be actually positioned such that the axis any particular cylinder • lies on the plane along which the first crankpin on the first crankshaft rotates. • lies on the plane along which the second crankpin on the second crankshaft rotates. • is perpendicular to the axis of rotation of the first crankshaft. • is perpendicular to the axis of rotation of the second crankshaft. Because of the angle a between the main shaft and the crankshafts, the helix angle of the gear (that are attached to the crankshaft) is made to lead the helix angle of the gear (that is attached to the main shaft) by an angle ct/2. [ i.e. if the helix angle of the gear attached to the main shaft is x°> then the helix angle of the gears attached to the three crankshaft is (x+ a/2)0]. The combination of the factors stated above result in the formation of an engine that is extremely flat and having a very low profile, combined with the advantage of having very few moving parts. BRIEF DESCRIPTION OF THE DRAWINGS Figure-1 shows the assembly of main shaft, crankshafts, pistons and cylinders. A cut section of the cylinder and sleeve is shown so as to expose the internal components. Figure-2 shows the schematic layout of the interlaced engine describing the position of the crankshaft and cylinders and the various angles between them. Figure-3 shows the crankshaft. Figure-4 shows the arrangement of the gears. Figure-5 shows views describing the working of one cylinder with two adjacent crankshafts. Figure-6 shows views showing the various timings between the crankshafts Figure-7 shows the exploded view of the engine showing all the engine components (excluding the carburetor). Figure-8 shows the assembled view of the engine with all the components (excluding the carburetor). PART LIST No. : Description 1 : Crankshaft 1-A : Crankshaft-A 1-B : Crankshaft-B 1-C : Crankshaft-C 2 : Crankpin 2-A1 : Crankpin-1 on Crankshaft-A 2-A2 : Crankpin-2 on Crankshaft-A 2-B1 : Crankpin-1 on Crankshaft-B 2-B2 : Crankpin-2 on Crankshaft-B 2-C1 : Crankpin-1 on Crankshaft-C 2-C2 : Crankpin-2 on Crankshaft-C 3 : Cylinder 3-AB : Cylinder lying between Crankshaft-A and Crankshaft-B 3-BC : Cylinder lying between Crankshaft-B and Crankshaft-C 3-AC : Cylinder lying between Crankshaft-A and Crankshaft-C 4 : Mainshaft 5 : Internal Ring Gear 6 : Pinion Gear 7 : Connecting Rods 8 : Piston 9 : Cylinder Sleeve 10 : Combustion Chamber 11 : Inlet Port 12 : Exhaust 13 : Crankcase Assembly 14 : Crankcase Cover 15 :Hub 16 : Inlet Mainfold 17 : Inlet Valve 18 : Stator 19 : High Tension Ignition Coil Unit 20 : Circuit Breaker Unit 21 : Spark Plugs DETAILED DESCRIPTION OF THE PREFFERED EMBODIMENTS The invention is an engine that has three crankshafts and three cylinders placed between them. The main shaft lies at the center of the equilateral triangle formed by the three crankshafts. The power derived from the crankshafts is transferred to the main shaft by means of pinion gears (attached to the crankshafts) and an internal ring gear or an external gear (attached to the main shaft). All the three crankshafts rotate in the same direction. The main shaft can be made to rotate in the same direction as that of the crankshafts by attaching an internal ring gear, or it can be made to rotate in a direction opposite to the crankshafts by attaching an external gear to it. The cylinders are placed between the crankshafts such that they formed an interlaced triangle. The basic layout of the engine is shown in Figure-2. The engine works on a two stroke cycle. For sake of simplicity, let us consider the working of just one of the cylinders (Cylinder-AB) which is shown in Figure-5A. The cylinder has a crankshaft placed at either end. The crankshafts are shown rotating in the anticlockwise direction. There are two pistons in the cylinder, which oppose each other and are connected to each of the crankshafts by a connecting rod. The section at the center of the cylinder, enclosed by the two pistons forms the combustion chamber. Rotation of the crankshaft causes the pistons to reciprocate within the cylinder. In Figure-5(A to E) a transverse section of the cylinder sleeve is shown. There is an inlet port to the left side and an exhaust port to the right side. These ports are placed around the entire circumference of the cylinder sleeve. It would be rather confusing if we consider the various timings for all the three crankshafts simultaneously, so let us consider all the timing with respect to Crankshaft-A. Crankshaft-B has to be placed at a phase difference of (180+5)° to Crankshaft-A, where 5 is the crank lead required between the two crankshafts. This enables the exhaust port to open before the inlet port opens and close at nearly the same time when the inlet port closes (providing unsymmetrical port timing). The value of 8 is usually kept between 10° to 20° however the derivation of this value is out of the scope of this description. In this particular description all the crank positions are shown considering 5 = 12°, however a different value can be used depending upon the use and operating requirements of the engine. In Figure-5A, Crankshaft-A is shown at 180° which is called as the Bottom Dead Center (BDC). At this stage the inlet port is completely open and the fresh charge is forced into the cylinder and the residual (exhaust) gases are forced out through the exhaust port. As the crankshaft rotates, the pistons cover both the inlet and exhaust ports thus closing them as shown in Figure-5B. Further rotation of the crankshaft causes the charge to get compressed. As the pistons reach near the Top Dead Center (TDC), the charge is ignited (see Figure-5C). This produces a rise in temperature and pressure in the cylinder and thus pushing the two pistons apart, thus delivering power to the crankshafts and making them rotate further. As the pistons move further away form each other, the exhaust port gets uncovered causing the burnt gases which are at high pressure to come out (see Figure-5D). As the rotation of the crankshafts proceeds, the inlet port also gets uncovered. This enables fresh charge to enter into the cylinder through the inlet port. This fresh charge pushes the remaining burnt gases out of the exhaust port until the whole cylinder gets filled with the fresh charge (see Figure-5E). The whole cycle then repeats itself. The engine is formed by joining together three such cylinders (described in Figure-5) to form an interlaced triangle. This creates the configuration shown in Figure-2. Each crankshaft will have two pistons connected to it (as in a V). For this configuration to work in a uniform manner, it is necessary that the three cylinders fire at uniform intervals for one complete revolution of the crankshaft, that is 360°/3 = 120° apart. For this the three crankshafts also have to be placed at a phase difference that is equal to each other, i.e. each of the crankshaft has to be placed at a phase difference of 120° from the adjacent one (see Figure-6B). Hence if crankshaft-A is at 0°, then crankshaft-B will be at 240° and crankshaft-C will be at 120°. However for the combustion cycle to work properly the crankshafts have to be placed at a phase difference of 192° (that is 180°+6) to each other (see Figure-6A). If we connect both the pistons on a particular crankshaft to the same crankpin and try to maintain a phase difference of 192° between the crankshafts, we can see that it works fine for two of the cylinders but in case of the third cylinder, the crankshafts will have to be placed 24° apart. It is obvious that the combustion cycle can't work at this phase difference and hence the third cylinder will be rendered useless. (The pistons will just keep on reciprocating without causing any appreciable change in volume within the cylinder for the two stroke combustion cycle to work). See Figure-6C The invention overcomes this problem by making use of a crankshaft that has two crankpins (instead of one) which are placed at an angle of 48° (that is 180 -120 -8)° to each other. In any particular cylinder, one piston will be attached to Crankpin-1 of the first crankshaft and the other piston will be attached to Crankpin-2 of the second crankshaft. See Figure-6D. In Figure-6D both the crankpins are shown in one plane. However if they are placed this way they will cause the connecting rods (that are connected to these crankpins) to fowl with each other and restrict each others motion. Because of this the pins have Jo be placed laterally apart form each other, in two different planes. The final shape of the crankshaft obtained is shown in Figure-3. Now the shape of the crankshaft poses yet another problem. In any particular cylinder one piston is attached to Crankpin-1 of the first crankshaft and the other piston is attached to Crankpin-2 of the second crankshaft. These two pins are places along different planes that are parallel but laterally apart from each other. The axis of the cylinder has to be made to lie along both these planes. In the invention this problem is addressed by inclining the three crankshafts to the main shaft by an angle a, such that the axis of the cylinder lies along these two planes and is perpendicular to the axis of rotation of the two crankshafts placed at either end (see Figure-2). The value of a is a function of 'the distance between two crankshafts' and 'the distance between the planes along which the two crankpins (of the same crankshaft) rotate". The resulting configuration that is obtained is shown in Figure-2. The cylinders and crankshafts interlace each other and hence the name "Interlaced Delta Engine". It should be noted that because of the inclination of the crankshaft, the angle between two adjacent cylinders increases by p since they are not placed along the same plane. The two adjacent cylinders are placed at an angle of (60+B)O to each other. See Figure-2. Here again p is a function of 'the distance between two crankshafts' and 'the distance between the planes along which the two crankpins (of the same crankshaft) rotate". The angle bejwejenjhe two crankpins on the same shaft also has to be increased to accommodate p. Hence the angle between the two crankpins has to be kept as (180-120-S + P)0. The gears that are used are also modified to accommodate the angle a between the crankshaft and the main shaft. The helix angle of the gears (that are attached to the crankshaft) lead the helix angle of the gear (that is attached to the main shaft) by an angle a/2, i.e. if the helix angle of the internal ring gear is x°, then the helix angle of the pinion gears is (x + A sectional view of the assembly of main shaft, crankshafts, pistons and cylinders is shown in Figure-1. In this view the cylinder and sleeve are cut along various sections so as to expose the internal components. The concept described above can be used for a spark ignited as well as a compression ignited cycle. The following section describes an engine that has been adapted to work on the spark ignited two stroke cyde. An exploded view of the engine with all its components is shown in Figure-7. The figure itself is self explanatory, showing all the components. The various systems of the engine have been designed such that they fit very neatly into a small and flat cylindrical space. The core of the engine is formed by three crankcases each of which accommodates a crankshaft and a cylinder sleeve inside which the pistons reciprocate. The crankcases are connected to each other with the aid of tie bolts. When assembled together, they formed the interlaced triangle. They are connected to each other from the outside by a common inlet manifold to which a standard carburetor can be attached. The crankcase has an opening at the bottom near the crankshaft into which a leaf type inlet valve is placed. The valve operates on the basis of pressure difference. When the pistons are in the upward motion, the pressure in the crankcase drops below that in the inlet manifold. This causes the inlet valve to open, causing the air-fuel mixture from the manifold to enter into the crankcase. When the pistons are moving downward, the pressure in the crankcase begins to increase. When it reaches a pressure that is higher than that in the inlet manifold, the leaf valve closes. Further downward motion of the pistons causes the crankcase pressure to increase. This continues till the inlet port gets uncovered and the air fuel mixture (which is compressed) in the crankcase is forced into the cylinder (combustion chamber) through the inlet port. It should be noted that the volume of air fuel mixture entering into the crankcase is equal to the volume displaced by two pistons. This is also equal to the volume that is required in the combustion chamber. Hence the crankcase itself is used as a scavenging pump and there is no need of a separate pump. (It should be noted that the arrangement shown above for supplying fuel can be replaced by a fuel injection pump.) Lubricating for the engine is provided by mixing oil with the air-fuel mixture. A hub is placed at the center of the three crankcases which has three arms that are attached to the base of the crankcase. An axel is placed at the center of the hub. About this axel, a circular disk is mounted which acts as the main shaft. The disc has openings in it, into which impeller blades are attached which act as a means of forced air cooling for the engine. The internal ring gear is also attached to this disc which meshes with the pinion gears attached to the three crankshafts. The crankshaft is designed such that it acts as a flywheel. The disc also acts as a secondary flywheel and hence the need of a separate flywheel is avoided. The disc also has permanent magnets that are placed along its circumference. A stator is placed in line with these magnets, between the disc and the inlet manifold. This acts as a means of providing electricity for the ignition system. A conventional ignition system (with circuit breakers placed about the axel) or an electronic ignition system (with sensors placed along the secondary flywheel) can be used. The engine has three separate exhaust mufflers that are attached to each of the crankcase. In Figure-8 the complete assembled front and rear (orthographic) view of the engine has been shown. The described above can be made to run for a compression ignited two stroke cycle by replacing the spark ignition system and carburetor by a fuel injection pump. Claim, 1. An interlaced delta engine comprising of a main shaft, three secondary crankshafts all rotating in the same direction, the three sec. Shafts form vertices of an equilateral triangle, the main shaft being located at centre of said triangle, each secondary crank shaft having two crank pins which lie on the plane perpendicular to respective crank shaft, three cylinders being placed between the crank shafts such that this apparently form the sides of the triangle, each cylinder has two pistons reciprocating within it and the space enclosed between the two pistons forming the combustion chamber, each piston being connected to corresponding crank shaft by means of a connecting rod, 2. An interlaced Delta engine as claimed in claim 1, wherein the three cylinders fire at regular intervals that are 120 apart from each other for one complete revolution of the crankshafts, which rotate at a phase difference of 120°to each other, 3. An interlaced delta engine as claimed in the above claims, wherein each crankshafts has two crankpins each placed along different planes of rotation and are positioned at an angle (180 - 120 -^ + p ) apart from each other, where is the crank lead required between the two crankshafts in a particular cylinder, 4. An interlaced delta engine as claimed in claim 3 wherein the crankshafts has pinion gear which meshes with a single gear attached to the main shaft, the main shaft is made to rotate in the same direction of the three crankshafts by attaching an internal ring gear to it, or is made to rotate in a direction opposite to the three crankshafts by attaching an external gear to it, 5. An interlaced delta engine as claimed in claim 1, wherein the three crankshafts are inclined at an angle to the main shaft. The angle enables the cylinders to be positioned such that, The axis of cylinder -AB lies on the plane along which crankpin -1A rotates, lies on the plane along which crankpin-2B rotates, is perpendicular to the axis of rotation of crankshaft-A is perpendicular to the axis of rotation of crankshaft-B The axis of cylinder -BC lies on the plane along which crankpin -IB rotates, lies on the plane along which crankpin -2C rotates, is perpendicular to the axis of rotation of crankshaft-B is perpendicular to the axis of rotation of crankshaft-C The axis of cylinder -AC, lies on the plane along which crankpin -2A rotates, les on the plane along which crankpin -1C rotates, is perpendicular to the axis or rotation of crankshaft-A is perpendicular to the axis of rotation of crankshaft -C the angle increases the angle between two adjacent cylinders by and the cylinders are actually placed at an angle (60+^) to each other, 6. an interlaced delta engine such as here in described with reference to the accompanying drawings, Dated this 1 lm day of august. 2004 (Mr. Prasad Jayanth Chaodankar)

Documents:

865-mum-2004-cancelled pages(21-2-2005).pdf

865-mum-2004-claims(granted)-(21-2-2005).doc

865-mum-2004-claims(granted)-(21-2-2005).pdf

865-mum-2004-correspondence(15-4-2005).pdf

865-mum-2004-correspondence(ipo)-(24-11-2006).pdf

865-mum-2004-drawing(21-2-2005).pdf

865-mum-2004-form 1(11-8-2004).pdf

865-mum-2004-form 19(11-8-2004).pdf

865-mum-2004-form 2(granted)-(21-2-2005).doc

865-mum-2004-form 2(granted)-(21-2-2005).pdf

865-mum-2004-form 3(11-8-2004).pdf

865-mum-2004-form 9(26-12-2005).pdf

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