TECHNICAL FIELD

[0001] The subject matter as described herein, in general, relates to internal combustion engines and, in particular, relates to an internal combustion engine having a common combustion chamber.

BACKGROUND

[0002] Conventionally, internal combustion (IC) engines find use in industrial, transport, and marine applications. A typical IC engine includes a cylinder block having one or more cylinder bores and a piston reciprocating in each of the cylinder bore. The reciprocating motion is imparted to the piston by expanding combustion products, which are produced as a result of ignition of charge in a combustion chamber of the IC engine. In such conventional IC engines, the combustion chamber is formed between a cylinder head, a top surface of the piston, and walls of the cylinder bore. The reciprocating motion of the piston is converted into a rotary motion of a crankshaft through a connecting rod. Further, the motion from the crankshaft is transmitted to the wheels through a drive train.

[0003] Usually, in a multi-cylinder IC engine, the cylinder bores are provided in such a way that central longitudinal axes of the cylinder bores, also referred to as cylinder axes, are parallel to each other and lie in one plane. Such an IC engine is referred to as an in-line cylinder engine. In certain other type of multi-cylinder engines, the cylinder axes of consecutive cylinders are inclined to each other, whereas the cylinder axes of alternate cylinders are parallel to each other. In such multi-cylinder engines, the cylinders are provided in two sets which are inclined to each other, forming a V-shaped configuration of the cylinders.

[0004] In addition, in few multi-cylinder engines, the two set of cylinders are inclined to each other at an angle of 180°. Therefore, the cylinder axes of the cylinders lie in the same plane, with the reciprocating motion of the pistons in the two set of cylinders occurring in mutually opposite directions. The pistons in such engines are connected to a single central crankshaft, from which the cumulative output power of all the pistons is obtained.

SUMMARY

[0005] An internal combustion (IC) engine having a common combustion chamber is disclosed herein. The IC engine includes a first cylinder bore and a first piston reciprocating in the first cylinder bore, the first piston driving a first crankshaft. The first crankshaft is disposed at a distal extreme end of the first cylinder bore and provides a primary drive to propel a vehicle. The IC engine further includes a second cylinder bore inclined to the first cylinder bore, a proximal extreme end of the first cylinder bore being adjacent to a proximal extreme end of the second cylinder bore. A second piston reciprocates in the second cylinder bore and drives a second crankshaft. The second crankshaft is disposed at a distal extreme end of the second cylinder bore and provides a secondary drive to operate at least one auxiliary component of the vehicle.

[0006] These and other features, aspects, and advantages of the present subject matter will be better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF DRAWINGS

[0007] The above and other features, aspects, and advantages of the subject matter will be better understood with regard to the following description, appended claims, and accompanying drawings where:

[0008] Fig. 1 illustrates a sectional view of an internal combustion (IC) engine, according to an embodiment of the present subject matter.

[0009] Fig. 2 illustrates a sectional view of the IC engine, according to another embodiment of the present subject matter.

DETAILED DESCRIPTION

[0010] The subject matter described herein relates to an internal combustion (IC) engine, according to an embodiment of the present subject matter. In an embodiment, the IC engine is a twin-cylinder engine.

[0011] Conventional IC engines usually have in-line cylinder bores having parallel cylinder axes or inclined cylinder axes, such that the combustion chamber is formed between a cylinder head and a top surface of a piston. The compression ratio of the IC engine, which is one of the factors that has direct bearing on the power generated by the IC engine, is dependent on the inherent structure of the IC engine. For example, the compression ratio is influenced by the shape of the cylinder head forming the combustion chamber.

[0012] Conventionally, to increase the compression ratio, and hence, the power generated, engines have been developed that have pistons in the cylinder bores, such that top surfaces of pistons face each other, and such engines are hereinafter referred to as facing piston engines. Such engines include two or more cylinder bores and cylinder axes of the two cylinder bores generally coincide, forming a central longitudinal axis of the cylinder bores. The pistons in the two bores are connected through connecting rods to two crankshafts in proximity of crankshaft ends of the respective cylinder bores. In one example, the crankshaft end of the cylinder bore can be an inner dead centre in case of a horizontally positioned cylinder bore or a bottom dead centre in case of vertically positioned cylinder bore, both positions being determined with respect to the crankshaft.

[0013] Further, a combustion chamber is formed between top surfaces of each of the facing pistons that are reciprocating in each cylinder bore, along with the walls of the cylinder bore, when the pistons are at proximal extreme ends of the respective cylinder bores. The proximal extreme end of the cylinder bore can be, for example, the top extreme end in case of a vertically disposed cylinder bore and outer dead centre in case of a horizontally disposed cylinder bore, with respect to the crankshaft. Such engines generally have a high compression ratio as the compression is achieved between the pistons, by the motion of the pistons in the respective cylinder bores approaching each other. As a result, such conventional engines generate high power.

[0014] However, such engines are longer because of the end-to-end orientation of the cylinder bores, and hence, are bulky. Further, the presence of two crankshafts at ends opposite to the proximal extreme ends of the respective cylinder bores adds to the weight of the engine. The large weight of the engine contributes to the overall weight of the vehicle and thereby reduces fuel economy of the vehicle. In addition, the high compression ratio of the engine involves large forces and requires large amount of cooling and lubrication. Hence, the lubricant consumption of the engine for cooling and lubrication is high.

[0015] Additionally, in the conventional facing piston engines, the power from one crankshaft is added to the power of the other crankshaft by using a crank train assembly, provided between the two crankshafts and disposed on one side of the engine. The crank train assembly includes a plurality of gears and fills the gap between the two crankshafts. The provision of the crank train assembly at one side of the engine, however, causes an imbalance of weight on one side of the engine. As a result of the imbalanced weight of the engine, the engine experiences high vibrations during operation. Further, large number of heavy components adds to the inertia of the engine, and hence, causes greater vibrations.

[0016] Further, the packaging or mounting of such engines, for example, on a two-wheeler, is usually done in such a way that the central longitudinal axis of the cylinder bores is almost parallel to a central axis of the vehicle. As a result of such packaging, the lubricant is not able to flow under the effect of gravity and requires a separate pump for lubricating and cooling the different parts of the engine. Further, due to the aforementioned packaging and orientation of the engine in the vehicle, stagnation of the lubricant takes place at the bottom of the piston and some oil may also seep into the combustion chamber when the vehicle, for example, the two-wheeler, is parked for long durations. As a result of the seepage, the lubricating oil may undergo combustion during operation of the engine. Hence, the emissions from the engine may not satisfy various norms and policies related to, for example, pollution control.

[0017] The present subject matter relates to an internal combustion (IC) engine having a common combustion chamber.

[0018] In an embodiment, the IC engine is a twin-cylinder IC engine. In said embodiment, the IC engine, referred to as an engine hereinafter, includes a cylinder block having at least two cylinder bores - a first cylinder bore and a second cylinder bore. The first cylinder bore and the second cylinder bore are provided in the cylinder block such that the two cylinder bores form a single continuous bore, separated by a centre piece which is formed as a ring. The ends of the first and the second cylinder bores adjacent to the centre piece are referred to as proximal extreme ends of the two cylinder bores. Further, the other extreme ends of the first and the second cylinder bores lying away from each other are referred to as distal extreme ends of the cylinder bores.

[0019] According to an aspect of the present subject matter, the first cylinder bore and the second cylinder bore are inclined to each other. For example, a central longitudinal axis of the first cylinder bore can be inclined to a central longitudinal axis of the second cylinder bore. Hence, the first cylinder bore and the second cylinder bore are formed as a bent continuous bore in the cylinder block. In one embodiment, the first cylinder bore and the second cylinder bore are inclined to each other in a vertical plane. However, in other embodiments, the two cylinder bores can be inclined to each other in other planes. Further, according to one embodiment, an included angle between the first cylinder bore and the second cylinder bore is less than 180°. In one example, the included angle is about 160°. The included angle can be understood as an angle formed between the central longitudinal axes of the first cylinder bore and the second cylinder bore, measured from the central longitudinal axis of the first cylinder bore in a counter-clockwise direction.

[0020] Further, a piston is disposed in each cylinder bore and reciprocates in the respective cylinder bore. The pistons provided in the first cylinder bore and the second cylinder bore are referred to as the first piston and the second piston, respectively. In a closest extreme position, the first and the second piston are adjacent to each other and to the centre piece at the proximal extreme ends of the first and the second cylinder bores. In an embodiment, in such a position, the first piston and the second piston, along with the centre piece, define the common combustion chamber. In an embodiment, at the distal extreme ends of the first cylinder bore and the second cylinder bore, a first crankshaft and a second crankshaft are disposed, respectively. The first piston is connected to the first crankshaft through a first connecting rod and, similarly, the second piston is connected to the second crankshaft through a second connecting rod.

[0021] During operation, the combustion of charge occurs in the common combustion chamber to provide a reciprocatory motion to the first and the second piston in the first and second cylinder bore, respectively. The reciprocatory motion of the first piston is transferred to the first crankshaft through the first connecting rod to provide a rotary drive to the first crankshaft. Similarly, the motion of the second piston is transferred to the second crankshaft through the second connecting rod to provide a rotating motion to the second crankshaft.

[0022] Further, according to an aspect of the present subject matter, the first and the second crankshafts can provide independent drives. In an embodiment, a primary drive is obtained from the first crankshaft. The primary drive can be understood as the drive used for propulsion of the vehicle on which the engine is mounted. On the other hand, the second crankshaft can be used to obtain a secondary drive which is used to drive auxiliary components associated with the engine, such as a fuel pump, a lubricating pump, or an alternator. According to an implementation, a size of the first cylinder bore is provided substantially similar to the size of the second cylinder bore to achieve substantially similar output at the first and second crankshafts. In another implementation, the size of the first cylinder bore and the size of the second cylinder bore are different, and hence, the output at the first crankshaft and the second crankshaft is different. In an example, the first cylinder bore can be provided with a larger diameter than the diameter of the second cylinder bore, since high output power is to be obtained at the first crankshaft to provide the primary drive.

[0023] Further, in an embodiment, the first crankshaft and the second crankshaft can be connected to each other through a synchronization mechanism. The synchronization mechanism can maintain a synchronous motion of the two crankshafts with reference to each other for operation of the engine, despite providing independent drives. As a result, the relative position of the pistons in the respective cylinder bores is synchronized so that the pistons are at the proximal extreme ends of the respective cylinder bores at an end of compression stroke of the engine.

[0024] With the independent operations of the first and second crankshafts, the crank train assembly used conventionally is not required. As a result, the overall weight of the engine and that of the vehicle is reduced. The reduction in the weight of the engine and of the vehicle facilitates in reducing the fuel consumption of the engine and enhances fuel economy of the vehicle.

[0025] Further, as a result of the inclined cylinder bores of the engine, the distance between centres of the first crankshaft and the second crankshaft is reduced, and the overall length of the engine is less than the overall length of a conventional facing piston engine of equivalent capacity. The reduction in the size of the engine helps reduce the inertia of the engine and assists in easy packaging of the engine on body of the vehicle, for example, a two-wheeled vehicle. In addition, the incline between the cylinder bores of the engine allows quick drainage of oil into an oil sump and reduces seepage of oil into the common combustion chamber of the engine when the vehicle is parked and avoids oil accumulation behind the piston while running.

[0026] Fig. 1 illustrates a schematic of a sectional view of an internal combustion (IC) engine 100 having a common combustion chamber (not shown), according to an embodiment of the present subject matter. According to said embodiment, Fig. 1 shows a longitudinal section of the IC engine 100, hereinafter referred to as engine 100.

[0027] According to an embodiment of the present subject matter, the engine 100 is a twin-cylinder internal combustion engine. In said embodiment, the engine 100 includes an engine block 102 having a first cylinder bore 104 and a second cylinder bore 106.

[0028] Further, at a distal end of the first cylinder bore 104, a first crankcase 108 is provided. The first crankcase 108 houses a first crankshaft 110, which is connected to a first piston 112, reciprocating in the first cylinder bore 104. The first piston 112 can be connected to the first crankshaft 110 through a first connecting rod 114. In an example, a small end 116 of the first connecting rod 114 is connected to the first piston 112 and a big end 118 of the first connecting rod 114 is connected to the first crankshaft 108. The first connecting rod 114 can be connected to the first crankshaft 110 at a crankpin (not shown in figure) of the first crankshaft 110.

[0029] Similarly, a second crankcase 120 is provided at a distal end of the second cylinder bore 106. A second crankshaft 122 is disposed in the second crankcase 120, and is connected to a second piston 124 through a second connecting rod 126. The second piston 124 is connected to a small end 128 of the second connecting rod 126 and the second crankshaft 122 is connected to a big end 129 of the second connecting rod 126. The second connecting rod 126 can be connected to a crankpin of the second crankshaft 122. The second piston 124 reciprocates in the second cylinder bore 106. In one embodiment, in which the engine 100 is disposed in a vertical direction, the distal ends of the cylinder bores 104 and 106 are bottom dead centres of the cylinder bores 104 and 106. In another embodiment, in which the engine 100 is disposed in a horizontal direction, the distal ends of the cylinder bores 104 and 106 are inner dead centres of the cylinder bores 104, 106.

[0030] In an embodiment, a first crank offset is provided between the first piston 112 and the first crankshaft 110 and a second crank offset is provided between the second piston 124 and the second crankshaft 122. In an embodiment, the first crank offset and the second crank offset can lie in a range of about 2 millimetre (mm) to 8 mm. In one example, the first crank offset and the second crank offset is about 5 mm. The provision of the crank offset between the piston 112, 124 and the crankshaft 110, 122 reduces load on joints between the piston 112, 124, the connecting rod 114, 126, and the crankshaft 110, 122. The reduction of load on the joints further decreases loss of power generated by the engine 100 at the joints. Further, the provision of the crank offset reduces oil churning in the engine 100. Further, the first crank offset and the second crank offset are provided in such a way that the first crankshaft 110 rotates in a direction opposite to the direction of rotation of the second crankshaft 122. The opposite directions of rotation of the first crankshaft 110 and the second crankshaft 122 reduce vibrations of the engine 100 and improve ride quality of the vehicle on which the engine 100 is mounted.

[0031] According to an aspect of the subject matter, the first cylinder bore 104 and the second cylinder bore 106 are inclined to each other. In one example, a first cylinder bore axis 130 and a second cylinder bore axis 132 are inclined to each other, such that an included angle a between the two axes 130 and 132 is less than 180°. In an embodiment, the included angle a is about 160°. The included angle can be understood as an angle formed between the first cylinder bore axis 130 and the second cylinder bore axis 132, measured from the first cylinder bore axis 130 in a counter-clockwise direction. In said example, the first cylinder bore axis 130 and the second cylinder bore axis 132 can be understood as the central longitudinal axes of the first cylinder bore 104 and the second cylinder bore 106, respectively.

[0032] As a result of the incline between the first cylinder bore 104 and the second cylinder bore 106, the distance between centres of the first crankshaft 110 and the second crankshaft 122 is reduced, and an overall length of the engine 100 is less than an overall length of a conventional opposed piston engine of equivalent capacity. The reduction in the size of the engine 100 helps reduce the weight of the engine 100 and assists in easy packaging of the engine 100 on body of the vehicle. In addition, the incline between the cylinder bores 104 and 106 also allows quick drainage of oil into an oil sump (not shown in figure) of the engine 100 and reduces seepage of oil into the common combustion chamber when the vehicle is parked.

[0033] In an implementation, the engine block 102 further includes a centre-piece 134, which separates the first cylinder bore 104 and the second cylinder bore 106. In said implementation, the centre-piece 134 is formed as a ring or an annulus. Further, the end surfaces of the centre-piece 134 are inclined to each other at an angle of 180-a. The end surfaces of the centre-piece 134 can be understood as the surfaces of the centre-piece 134 adjoining the first cylinder bore 104 and the second cylinder bore 106, respectively. The ends of the first cylinder bore 104 and the second cylinder bore 106 adjoining the centre-piece 134 are referred to as proximal extreme ends of the cylinder bores 104 and 106. Further, according to an embodiment, the engine block 102 is formed as a single component having the first cylinder bore 104, the first crankcase 108, the second cylinder bore 106, the second crankcase 120, and the centre-piece 134. In another embodiment, the engine block 102 is formed as a plurality of engine block portions, each engine block portion having the cylinder bore 104, 106 and the crankcase 108, 120 formed integrally therein. In said embodiment, the centre¬piece 134 is positioned between the cylinder block portions. In yet another embodiment, the cylinder bores 104 and 106, the crankcases 108 and 120, and the centre-piece 134 are formed separately and fastened together.

[0034] During operation of the engine 100, the first piston 112 and the second piston 124 are at the proximal extreme ends in the respective cylinder bores 104 and 106, at the end of a compression stroke of the engine 100. At the end of the compression stroke, i.e., when the compression of charge is almost complete, a top surface 136 of the first piston 112 and a top surface 138 of the second piston 124 are adjacent to each other. In such a position of the pistons 112 and 124, the top surface 136 and the top surface 138 of the second piston 124, along with an inner lateral wall of the centre-piece 134, define the common combustion chamber therebetween. In an implementation, the common combustion chamber, when formed, includes compressed charge.

[0035] According to an embodiment, a first concave profile is provided on the top surface 136 of the first piston 112 and, similarly, a second concave profile is provided on the top surface 138 of the second piston 124, and the common combustion chamber is defined by the first and the second concave profiles. In another embodiment, the concave profile can be provided on the top surface of either the first piston 112 or the second piston 124 to define the common combustion chamber. In said embodiment, the common combustion chamber formed between the first piston 112 and the second piston 124 is hemispherical and formed as a bowl-shaped common combustion chamber. In another embodiment, the common combustion chamber is formed in the shape of a sphere. It will be understood that, in other embodiments, the common combustion chamber can be formed in other shapes, such as oval, conical, and pent-roof shape.

[0036] Additionally, an ignition element (not shown in figure) is provided in the common combustion chamber to achieve combustion of the compressed charge in the common combustion chamber. In one example, in case of a spark ignition engine, the ignition element can be a spark plug, whereas in case of a compression ignition engine, the ignition element can be a glow plug. In an embodiment, the ignition element is disposed in a through-opening in a lateral wall of the centre-piece 134. In said embodiment, the ignition element is disposed in the common combustion chamber in such a way that substantially complete combustion of the charge can be achieved in the common combustion chamber. In another embodiment, the engine 100 can include more than one ignition elements disposed in the common combustion chamber. It will be understood that, in other embodiments, a number of ignition elements can be provided in the common combustion chamber, so as to achieve a substantially complete combustion of the charge in the common combustion chamber.

[0037] Further, during operation of the engine 100, the combustion of charge in the common combustion chamber causes an expansion of combustion products, which thrusts the pistons 112 and 124 away from the proximal extreme ends and towards the distal ends. The reciprocatory motion of the pistons 112 and 124 in the respective cylinder bores 104 and 106 is transferred to the respective crankshafts 110 and 122. The reciprocatory motion of the pistons 112 and 124 is transferred through the respective connecting rods 114 and 126 and converted into a rotational motion of the respective crankshafts 110 and 122. Further, the rotating crankshafts 110 and 122 can further provide be used for driving the vehicle as well as various auxiliary components associated with the engine 100.

[0038] According to an aspect of the present subject matter, the first crankshaft 110 and the second crankshaft 122 can provide independent drives. In an implementation, the first crankshaft 110 can provide a primary drive, for example, for propelling the vehicle and the second crankshaft 122 can provide a secondary drive for operating the auxiliary components associated with the engine 100.

[0039] In an embodiment, a size of the first cylinder bore 104 is substantially same as a size of the second cylinder bore 106. For example, the first cylinder bore 104 and the second cylinder bore 106 can have substantially similar bore diameters and bore lengths. In said example, the first piston 112 and the second piston 124 can have substantially same diameters and cover substantially equal stroke lengths during reciprocating motion in the respective cylinder bores 104 and 106. With the provision of substantially same sizes of the first cylinder bore 104 and the second cylinder bore 106, substantially same output power can be obtained at the two crankshafts 110 and 122. In another embodiment, the first cylinder bore 104 and the second cylinder bore 106 can have different sizes. The latter embodiment is discussed in detail with reference to Fig. 2.

[0040] Further, since the first crankshaft 110 and the second crankshaft 122 can provide independent drives, in an embodiment, the two crankshafts 110 and 122 can be coupled to each other through a simple synchronization mechanism (not shown in figure). The synchronization mechanism is provided to maintain a synchronous motion of the crankshafts 110 and 122 with respect to each other. The harmonization between the motions of the first crankshaft 110 and the second crankshaft 122 can facilitate in maintaining synchronization between the relative position of the first piston 112 in the first cylinder bore 104 with respect to the relative position of the second piston 124 in the second cylinder bore 106. For example, the first piston 110 reaches the proximal extreme end of the first cylinder bore 104 at the almost the same instant as the second piston 124 reaches the proximal extreme end of the second cylinder bore 106, to achieve effective compression and combustion of charge and a smooth operation of the engine 100.

[0041] In an example, the synchronization mechanism connecting the two crankshafts 110 and 122 is a connecting link. However, it can be understood that the synchronization mechanism can be a simple gear assembly, a chain drive assembly, or a toothed belt for synchronizing the motion of the two crankshafts 110 and 122.

[0042] According to another embodiment, size of the first cylinder bore 104 and that of the second cylinder bore 106 can be dimensioned in such a way that synchronized motion of the first piston 112 and the second piston 124 in the first cylinder bore 104 and the second cylinder bore 104, respectively, is achieved. Accordingly, the size of the first cylinder bore 104 can be in proportion to the size of the second cylinder bore 106. For example, the first cylinder bore 104 can have a bore diameter and a bore length in proportion with the bore diameter and the bore length of the second cylinder bore 106 to provide a synchronized motion between the first and the second pistons 112 and 124 in the respective bores 104 and 106.

[0043] In addition, according to an embodiment of the present subject matter, a first sleeve and a second sleeve (both not shown in figure) are disposed in the first cylinder bore 104 and in the second cylinder bore 106, respectively. In an embodiment, the first sleeve and the second sleeve are disposed in the respective cylinder bore 104, 106 such that the sleeve is capable of sliding in the respective cylinder bore 104, 106 along a direction of the cylinder bore axis 130, 132. The sleeves may serve as a liner for the first cylinder bore 104 and the second cylinder bore 106, respectively. In an embodiment, the engine 100 includes a first actuator and a second actuator assembly (both not shown in figure) to actuate the first sleeve and the second sleeve, respectively.

[0044] Each of the actuator assemblies can include a rocker arm assembly and a cam. The cam can be mounted on a camshaft. Further, a first gear train can be coupled to the camshaft and provides a drive to the camshaft, and hence, to the cam from the crankshaft 110, 122. Further, with the rotation of the camshaft, rotation of the cam is achieved. The cam actuates the rocker arm assembly. In turn, a rocker arm of the rocker arm assembly actuates the sleeve in the cylinder bore 104, 106. In another embodiment, the actuator assemblies can include electromagnetic actuators. In other embodiments, the actuator assemblies can include other types of actuators, such as rack and pinion-type actuators.

[0045] In an embodiment, the sleeves in the first cylinder bore 104 and the second cylinder bore 106 can provided with one or more apertures for allowing induction of charge and escape of combustion products from the two cylinder bores 104 and 106, respectively. Further, the engine block 102 includes one or more inlet ports (not shown in figure) that are connected to a fuelling system (not shown in figure) of the engine 100. For example, the fuelling system may include a carburettor or a fuel injection system. In an implementation, the actuation of the first sleeve in the first cylinder bore 104 regulates an opening and closing of the inlet ports in the engine block 102. In said implementation, the actuator assembly can align the apertures in the first sleeve with the inlet ports to open the inlet ports and allow entry of charge into the first cylinder bore 104. Further, the actuator assembly can align the second sleeve with one or more exhaust ports in the engine block 102 to open the exhaust ports and to allow combustion products to escape.

[0046] Fig. 2 illustrates the engine 100, according to another embodiment of the present subject matter. According to said embodiment, the first cylinder bore 104 and the second cylinder bore 106 have different dimensions so that different outputs can be achieved at the two crankshafts 110 and 122. Along with achieving different outputs at the two crankshafts 110 and 122, the provision of differently sized cylinder bores 104 and 106 facilitates in reduction of fuel consumption of the engine 100.

[0047] According to an implementation, the first cylinder bore 104 can have a greater bore diameter and a greater bore length than those of the second cylinder bore 106. In said implementation, the first piston 112 traverses a greater stroke length than the second piston ^ 124. Further, with the provision of different sizes of the first cylinder bore 104 and the second cylinder bore 106, different output power can be obtained at the two crankshafts 110 and 122. In said implementation, a greater output power is obtained at the first crankshaft 110 than the output power that is obtained at the second crankshaft 122, as a result of the large size of the first cylinder bore 104. In an implementation, a radius of rotation of the crankpin of the second crankshaft 122, that is, the distance of the crankpin from a central longitudinal axis, is less than a radius of rotation of the crankpin of the first crankshaft 110.

[0048] Further, since a large output power is obtained from the first crankshaft 110, the first crankshaft 110 can be used to obtain the primary drive and the smaller output power obtained from the second crankshaft 122 can be used for providing the secondary drive. The primary drive can be used for propulsion of the vehicle and the secondary drive can be used for driving auxiliary components connected with the engine and functioning to operate the engine 100 and the vehicle. In an example, the auxiliary components driven by the second crankshaft 122 can include a fuel pump, a cooling pump, a compressor, a lubricating pump, or electrical components, such as an alternator.

[0049] According to an embodiment, to provide the primary drive to a vehicle, the first crankshaft 110 can be operatively coupled to wheels of the vehicle. According to an implementation, the first crankshaft 110 can be coupled to the wheels through a drive train of the vehicle. In an example, in case of the vehicle being a two-wheeled or a three-wheeled vehicle, the drive train can include a flywheel, a gear box, a clutch, and a chain drive. In another example, in case of the vehicle being a four-wheeled vehicle, the drive train can include the flywheel, the gearbox, the clutch, a propeller shaft, speed reduction gears, and a differential.

[0050] It will be understood that although the engine 100 has been described as a twin-cylinder engine, i.e., with reference to the two cylinder bores 104 and 106, the engine 100 can have more than two cylinder bores. In such an embodiment, the engine 100 can be understood to include a plurality of twin-cylinder engines similar to the engine 100 as described above with reference to Fig. 1. Further, in said embodiment, the engine 100 includes a first set of cylinder bores and a second set of cylinder bores, and each set of cylinder bores includes a plurality of cylinder bores.

[0051] Further, as will be understood from the foregoing description, the engine 100 can be implemented in vehicles, such as two-wheelers, three-wheelers, and four wheelers.

[0052] Although the subject matter has been described in considerable detail with reference to certain embodiments thereof, other embodiments are possible. It is to be understood that the appended claims are not necessarily limited to the features described herein. Rather, the features are disclosed as embodiments of the internal combustion engine 100.

I/We claim:

1. An internal combustion (IC) engine (100) having a common combustion chamber, the
IC engine (100) comprising:

a first cylinder bore (104);

a first piston (112) reciprocating in the first cylinder bore (104), the first piston (112) driving a first crankshaft (110), wherein the first crankshaft (110) is disposed at a distal extreme end of the first cylinder bore (104) and provides a primary drive to propel a vehicle;

a second cylinder bore (106), wherein a proximal extreme end of the first cylinder bore (104) is adjacent to a proximal extreme end of the second cylinder bore (106);

a second piston (124) reciprocating in the second cylinder bore (106), the second piston (124) driving a second crankshaft (122), wherein the second crankshaft (122) is disposed at a distal extreme end of the second cylinder bore (106) and provides a secondary drive to operate at least one auxiliary component of the vehicle.

2. The IC engine (100) as claimed in claim 1, wherein the first cylinder bore (104) is inclined to the second cylinder bore (106).

3. The IC engine (100) as claimed in claim 1, wherein the first cylinder bore (104) and the second cylinder bore (106) have substantially same size.

4. The IC engine (100) as claimed in claim 1, wherein the first cylinder bore (104) and the second cylinder bore (106) have different size.

5. The IC engine (100) as claimed in claim 1, wherein the first crankshaft (110) is coupled to the second crankshaft (122) through a synchronization mechanism to synchronize a motion of the first crankshaft (110) with a motion of the second crankshaft (122).

6. The IC engine (100) as claimed in claim 1, wherein the second crankshaft (122) is coupled to at least one of a fuel pump, a compressor, a lubricant pump, and an alternator.

7. The IC engine (100) as claimed in claim 1, wherein a size of the first cylinder bore (104) is in proportion to a size of the second cylinder bore (106) to achieve a synchronization in a motion of the first crankshaft (110) and a motion of the second crankshaft (122).

8. The IC engine (100) as claimed in claim 1, wherein a radius of rotation of a crankpin of the first crankshaft (110) is greater than a radius of rotation of a crankpin of the second crankshaft (122).

9. A vehicle comprising the IC engine (100) as claimed in one of the preceding claims.

10. A two-wheeler comprising the IC engine (100) as claimed in one of the preceding claims.