Claims:
I/We Claim:
1. An internal combustion engine (180) comprising:
at least one crankcase (201) portion, said at least one crankcase (201) portion receiving a crankshaft (210);
at least one crankshaft bearing (219) for supporting said crankshaft (210) on said at least one crankcase (201) portion;
at least one oil pump (215) for supplying lubrication oil (300) from an oil sump (212) to other components of said internal combustion engine (180), said at least one oil pump (215) being disposed on said crankcase (201) substantially below said at least one crankshaft bearing (219);
one or more pockets (228, 229) formed on said crankcase (201) for receiving said lubrication oil (300) from at least one driving gear (213, 221) of said at least one oil pump (215);
a combination lubricating passage (232) is configured on the engine assembly,
wherein,
said combination lubricating passage (232) being formed by a fluidic communication connection between an oil groove passage (230) formed as a part of at least a portion of an oil pump cover assembly (220) portion and a first cross drilled passage (231) formed as a part of a drilled hole in at least a portion of said crankcase portion (201).
2. The internal combustion engine (180) as claimed in claim 1, a second groove part (230a) of said oil groove passage (230) being cast on said at least a portion of oil pump cover assembly (220) of said crankcase (201), said second groove part (230a) receiving said lubrication oil (300) from said one or more pockets (228, 229) and allowing passage of said lubrication oil (300) to said first cross drilled passage (231), said first cross drilled passage (231) allowing lubrication oil to flow from said oil groove (230) to an oil filter pocket (233) formed on said at least one crankcase (201) portion, and said oil groove passage (230), bypasses said at least one crankshaft bearing (219).
3. The internal combustion engine (180) as claimed in claim 1, wherein said oil groove passage (230) and said first cross drilled passage (231) together form a lubrication passage (232).
4. The internal combustion engine (180) as claimed in claim 3, wherein said oil groove passage (230) of said lubrication passage (232) lies in a region below a second plane (LL) defined as a plane passing horizontal through a crankshaft axis (210).
5. The internal combustion engine (180) as claimed in claim 2, wherein said second groove part (230a) of said oil groove passage (230) is covered by means of a first groove part (230b), wherein said first groove part (230b) is casted on an oil pump cover assembly (220).
6. The internal combustion engine (180) as claimed in claim 1, wherein said first cross drilled passage (231) is operably connected on at least one end of said oil groove passage (230).
7. The internal combustion engine (180) as claimed in claim 2, wherein said one or more pockets (228, 229) include an oil pump outlet pocket (228) and an oil pump inlet pocket (229).
8. The internal combustion engine (180) as claimed in claim 1, wherein said at least one oil pump (215) being disposed at a bottom end of said internal combustion engine (180).
9. The internal combustion engine as claimed in claim 1, wherein said oil filter pocket (233) is disposed at an upper half of said crankcase (201), and wherein said oil filter pocket (233) is disposed substantially above said at least one crankshaft bearing (219) when viewed from a side of said internal combustion engine (180).
10. The internal combustion engine (180) as claimed in claim 1, wherein said oil filter pocket (233) is disposed on a cover clutch (207c) of said internal combustion engine (180).
11. The internal combustion engine (100) as claimed in claim 1, wherein said at least one driving gear (213, 221) of said at least one oil pump (215) is enclosed within an at least one oil pump cover assembly (220) mounted on said at least one crankcase (201).
12. The internal combustion engine (180) as claimed in claim 10, wherein said at least one oil pump cover assembly (220) includes a first groove part (230b) and a second groove part (230a).
13. The internal combustion engine (180) as claimed in claim 11 wherein, said first groove part (230b) is casted on said at least one crankcase (201).
14. The internal combustion engine (180) as claimed in claim 11, wherein said first groove part (230a) and said second groove part (230a) lies in a first region (A), wherein said first region (A) being a region of said oil pump cover assembly (220) extending outwardly beyond a first plane MM.
15. The internal combustion engine (180) as claimed in claim 14, wherein said a clutch assembly (207) includes one or more clutch plates (207a), a clutch hub (207b), and a cover clutch (207c).
16. The internal combustion engine (180) as claimed in claim 14, wherein said at least one oil pump (215) is driven by one or more driving gear (213, 221) provided on a clutch assembly (207) of said internal combustion engine (180), wherein said cover clutch (207c) include a cover clutch first part (207cc) and a cover clutch second part (207ccc).
17. The internal combustion engine (180) as claimed in claim 14, wherein an oil filter pocket (233) being disposed on said cover clutch second part (207ccc).
18. The internal combustion engine (180) as claimed in claim 1, wherein said first cross drilled passage (231) provided on said at least one crankcase (201), is sealed on one end by an elastic member (226) of a cylinder block (202) of said internal combustion engine (180).
19. The internal combustion engine (180) as claimed in claim 1, wherein said oil lubricating passage (232) so formed by a combination of said first cross drilled passage (231) and an oil cast passage (230) has a Length / Depth ratio for the drill portion in the range of 30:1 to 10:1.
, Description:TECHNICAL FIELD
[0001] The present subject matter described herein generally relates to a vehicle, and particularly but not exclusively relates to an internal combustion engine of a vehicle.
BACKGROUND
[0002] Typically, two-wheeler engine acts as a power source for the two-wheeler. The two-wheeler engines are usually two-stroke or four-stroke engines. The main components of the engine comprise of a cylinder head, an engine block, and a crank case. The internal components of the engine include a crankshaft, one or more connecting rods, one or more pistons, a spark plug, a fuel injector, one or more intake and exhaust valves, a cam shaft, and a timing chain or belt.
[0003] The two stroke engines are usually used because of their cost efficiency and lighter built, in vehicles like go-karts. The two-stroke single cylinder engine typically has one piston and a crankcase. In such engines, the crankcase is used for the gas exchange. The two-stroke engine also has a spark plug and an intake as well as an exhaust port. A crucial difference between the two stroke and the four-stroke engine lies in the presence of a transfer port in the two-stroke engine.
[0004] The two-stroke engine completes a power cycle with two strokes (up and down movements) of the piston during only one crankshaft revolution. In the first stroke cycle, a first fuel air mixture is drawn via the intake port. Therefore, the fuel air mixture is added to the existing mixture in the crankcase. At the same time the mixture is compressed in the combustion chamber and ignited by the spark plug, which further initiates the second cycle. During the second cycle, the hot air expands and pushes the piston downwards increasing the volume of the combustion chamber resulting in the release of hot burned gases from the exhaust port of the ongoing cycle. Because of the downward motion of the piston, a fresh air fuel mixture which was sucked in during the compression of the previous cycle is now forced into the combustion chamber via a transfer port. At the same time the fresh air fuel mixture scavenges out the remains of the burned gases from the previous combustion cycle via an opened exhaust port.
[0005] In a four-stroke engine, the power is produced in the engine by a four-stroke process. Firstly, the moment, the piston moves to the bottom dead centre of the engine, a vacuum is created in the combustion chamber. Due to the created vacuum, the air fuel mixture is sucked in via the intake valve (s), filling the combustion chamber with a new fresh charge enriched with oxygen and hydrocarbons. Secondly, the intake valve closes and the piston moves upward towards the top dead centre resulting in gradual compression of the air fuel mixture. This compression stroke develops a pressure within and increases the in-cylinder temperature making the air fuel mixture ready for combustion.
[0006] While the compression stroke is in progress, and the piston is few crank degrees away from reaching the top dead centre, an approximate of 25000 V of energy stepped up by the ignition coil, is transferred to the spark plug generating a spark across its electrodes, which further ignites the compressed charge. Further, the burned charge followed by a flame front travels all along the combustion volume and reaches the last unburned charge molecule, resulting in complete combustion by igniting the whole mixture. Lastly, in the exhaust stroke, i.e., the fourth stroke, the piston moves from the bottom dead centre to the top dead centre, pushes the burned exhaust gases out of the combustion chamber via the exhaust valves.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The detailed description is described with reference to an embodiment of a vehicle with an internal combustion engine along with the accompanying figures. The same numbers are used throughout the drawings to reference like features and components.
[0008] Fig. 1 illustrates a side view of a vehicle in accordance with an embodiment of the present invention.
[0009] Fig. 2 illustrates a side view of the internal combustion engine, according to an embodiment of the present subject matter.
[00010] Fig. 3a to Fig. 3b illustrates a side view of the internal combustion engine elaborating the internal parts of the internal combustion engine, according to an embodiment of the present subject matter.
[00011] Fig. 4a to Fig. 4b illustrates exploded views of the internal combustion engine elaborating the internal parts of the internal combustion engine, according to an embodiment of the present subject matter.
[00012] Fig. 5 illustrates a sectional view of the internal combustion engine while elaborating the internal parts of the internal combustion engine, according to an embodiment of the present subject matter.
[00013] Fig. 6a and Fig. 6b illustrate a sectional view of the internal combustion engine while elaborating the internal parts of the internal combustion engine, according to an embodiment of the present subject matter.
[00014] Fig. 7 illustrates sectional views of the oil pump cover assembly of an internal combustion engine, according to an embodiment of the present subject matter.
[00015] Fig. 8a to Fig. 8c illustrates a sectional view of the internal combustion engine while elaborating the internal parts of the internal combustion engine, according to an embodiment of the present subject matter.
[00016] Fig. 9a and Fig. 9b illustrates parts of a clutch assembly of an internal combustion engine, according to an embodiment of the present subject matter.
DETAILED DESCRIPTION
[00017] Typically, the internal combustion engine includes a cylinder block, a crankcase assembly, a crankshaft, a cam shaft, a gear oil pump drive and an oil pump assembly. As per some internal combustion engine constructions, on the left-hand side of the crankshaft, the gear oil pump drive is mounted through press-fitting process and the gear oil pump drive is mated with the oil pump assembly.
[00018] Usually, the gear oil pump drive includes a primary driving gear, and a secondary driving gear. The oil pump assembly includes an oil pump cover assembly and an oil pump. The gear oil pump drive and the oil pump assembly are assembled together on an oil pump shaft. Since the gear oil pump drive is placed in proximity of the crankshaft, the rotation of the crankshaft initiates the staring of the gear oil pump drive along with the oil pump assembly. This ultimately results in the movement of lubricant oil from an oil sump of the internal combustion engine, which usually stores the lubrication oil. The movement of the lubricant oil across the lubrication passages provided in the internal combustion engine aids in proper lubrication of the system and also cools the piston, the plurality of piston cylinder wall and other parts of the internal combustion engine.
[00019] Usually, a lubrication filter passage is connected to the lubrication passages from the oil sump through a cross drill from a crankcase top surface of the internal combustion engine. The oil pump pressurizes the lubrication oil present in the oil sump and delivers the lubrication oil to the oil filter along a desired path provided in the crankcase.
[00020] Some known arts disclose about creation of such lubrication paths in the crankcase of the internal combustion engine by using two cross drills which connects the oil pump and the oil filter passage. One of the cross drilling is done from the oil pump side of the internal combustion engine and the other cross drilling is done from the crankcase top surface of the internal combustion engine. However, usage of such multiple drills usually creates problematic intersection points.
[00021] Issues like burr formation due to machining occurs at such cross drills intersection points due to machining. At several instances usage of such cross drills also results in the oil flow area reduction due to making tolerance, which ultimately affects the oil flow rate.
[00022] Some other known arts also disclose that the drilled hole for carrying the lubrication oil from the oil pump to the oil filter, and the longest drilled hole from the oil filter to the heat exchanger being drilled together within the crankcase. However, such drilling can only be done in particular internal combustion engines, which are designed in such a manner that the drilling process can be done from both the top surface and the bottom surface of the crankcase, while ensuring that no internal part obstructs the drilling of the lubrication passage.
[00023] Moreover, the longest drilled hole from the oil filter and the heat exchanger can only be achieved in internal combustion engine having no interfering components in between the long lubrication path. Therefore, the lubrication path achieved in such an engine is both long and straight as it is not required to bypass any interfering components.
[00024] However, there are other known arts disclosing internal combustion engines having the oil pump and the oil filter being placed substantially closer to each other. Therefore, in such internal combustion engines the drilled hole connecting the oil pockets formed around the rotor of the oil pump and the oil filter is shorter in nature and straighter as compared to above stated internal combustion engines mentioned in the above stated known arts. Therefore, in such internal combustion engines the necessity to bypass any interfering components is obliviated.
[00025] The position of the oil pump and the oil filter disposed on the crankcase becomes an important factor in determining the type of oil passage to be drilled within the crankcase of the internal combustion engine. Therefore, in internal combustion engine using a wet sump lubrication system, where the oil pump and the oil filter are placed substantially away from each other, and the passage in between the oil pump and the oil filter includes one or more internal parts, the drilling of lubrication passage, while ensuring uniform passage, becomes a daunting task. Moreover, drilling longer holes on the crankcase has its own disadvantages as explained in the preceding paragraphs.
[00026] Further, presence of any interfering components of the internal combustion engine between the oil pump and the oil filter also negatively impacts the formation of straight passage made by drilled holes for carrying lubrication oil from the oil pump to the oil filter.
[00027] Hence, there is a need to address above circumstances and problems of the known arts.
[00028] The present subject matter has been devised in view of the above circumstances as well as solving other problems of the known art.
[00029] The present subject matter discloses an improved lubrication oil flow path from the oil pump located in proximity of the oil sump region to the oil filter through an oil filter passage in an internal combustion engine that uses wet sump lubrication system.
[00030] As per an aspect the present subject matter discloses a combination lubricating passage configured on the engine assembly. The combination oil groove passage being formed by a fluidic communication connection between a oil groove passage formed as a part of at least a portion of an oil pump cover assembly portion and a first cross drilled passage formed as a part of a drilled hole in at least a portion of the crankcase portion.
[00031] As per an aspect of the present embodiment, the internal combustion engine comprises of at least one crankcase portion and the at least one crankcase portion receives a crankshaft; at least one crankshaft bearing for supporting the crankshaft on the at least one crankcase portion; and at least one oil pump for supplying lubrication oil from an oil sump to other components of the internal combustion engine, at least one oil pump being disposed on the crankcase substantially below the at least one crankshaft bearing.
[00032] As per another aspect of the present embodiment, the internal combustion engine further comprises of one or more pockets formed on the crankcase for receiving the lubrication oil from at least one rotor of the at least one oil pump.
[00033] As per another aspect of the present embodiment, an oil groove is casted i.e. integrally configured during crankcase casting process, on at least one crankcase portion. The oil groove receives the lubrication oil from the one or more pockets and allows passage of the lubrication oil to a first cross drilled passage. The first cross drilled passage allows the oil to flow from the oil groove to an oil filter pocket formed on the at least one crankcase portion, and the oil groove bypasses the at least one crankshaft bearing.
[00034] As per an alternate embodiment of the present subject matter, the at least one oil pump is disposed at a bottom end of the internal combustion engine.
[00035] As per another alternate embodiment of the present subject matter, the oil filter pocket is disposed at an upper half of the crankcase, and wherein the oil filter is disposed substantially above at least one crankshaft bearing when viewed from a side of the internal combustion engine.
[00036] As per another alternate embodiment of the present subject matter, the oil filter is disposed on a cover clutch of the internal combustion engine.
[00037] As per another alternate embodiment of the present subject matter, the at least one rotor of the at least one oil pump is enclosed within an at least one oil pump cover mounted on the at least one crankcase. The at least one oil pump cover includes an extension member covering the oil groove casted on the at least one crankcase.
[00038] As per another alternate embodiment of the present subject matter, the at least one oil pump is driven by a gear member provided on a clutch assembly of the internal combustion engine.
[00039] As per another alternate embodiment of the present subject matter, the cross drilled passage provided on the at least one crankcase is sealed on one end by a gasket member of a cylinder block of the internal combustion engine.
[00040] Exemplary embodiments detailing features regarding the aforesaid and other advantages of the present subject matter will be described hereunder with reference to the accompanying drawings. Various aspects of different embodiments of the present invention will become discernible from the following description set out hereunder. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. It should be noted that the description and figures merely illustrate principles of the present subject matter. Various arrangements may be devised that, although not explicitly described or shown herein, encompass the principles of the present subject matter. Moreover, all statements herein reciting principles, aspects, and examples of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof. Further, it is to be noted that terms “upper”, “down”, “right”, “left”, “front”, “forward”, “rearward”, “downward”, “upward”, “top”, “bottom”, “exterior”, “interior” and like terms are used herein based on the illustrated state or in a standing state of the two wheeled vehicles with a driver riding thereon. Furthermore, arrows wherever provided in the top right corner of figure(s) in the drawings depicts direction with respect to the vehicle, wherein an arrow F denotes front direction, an arrow R indicates rear direction, an arrow Up denotes upward direction, an arrow Dw denotes downward direction, an arrow RH denotes right side, and an arrow LH denotes left side. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
[00041] Fig. 1 illustrates a side view of a vehicle 100 in accordance with an embodiment of the present invention. The vehicle 100 includes a frame assembly (not shown) to support different parts of the vehicle 100. In an upper portion of the frame assembly (not shown), a handlebar assembly 115 is rotatably integrally connected to the steering shaft (not shown). The handlebar assembly 115 is used to steer the vehicle 100 and is connected to a front wheel 185 through the steering shaft (not shown) and a front fork assembly (not shown). An upper portion of the front wheel 185 is covered by a front fender 190 which prevents mud and water from getting deflected towards the steering shaft (not shown). Further, the front fork assembly ( 195) is supported on the front fender 190 by means of a brace fender (not shown).
[00042] In a front portion of the frame assembly (not shown) a fuel tank assembly 120 is arranged immediately behind the handlebar assembly 115 and is disposed over a first power source, for example an internal combustion engine 180. A seat assembly 125 is placed behind the fuel tank assembly 120. The seat assembly 125 includes a front rider seating portion and a pillion rider seating portion. The pillion rider seating portion is placed on the rear part of the frame assembly (not shown), where the rear part of the frame assembly (not shown) is covered by the tail cover assembly (not labeled).
[00043] For the safety of the rider and in conformance with the traffic rules, a headlamp assembly 105 that includes a headlamp 110 and front indicator lights 140a are provided in the front portion of the vehicle 100. On the rear portion of the two wheeled vehicle 100 a tail lamp (not labeled) and rear indicator light 140b are provided on the rear portion of the tail cover assembly (not shown). Above a tail cover assembly 130 and behind the seat assembly 125 a pillion handle 135 is provided for the pillion rider to grab.
[00044] Suspension systems are provided for comfortable steering of the two wheeled vehicle 100 on the road. A front suspension assembly 195 serves as rigidity component for the front portion of the vehicle 100 just like the frame assembly (not shown). The front suspension assembly 195 clamped to the head tube (not shown) through an upper bracket (not labelled) and a lower bracket (not labelled) is capable of being moved to the left and right. Further, a rear suspension system 160, which is a hydraulic damped arrangement, is connected to the frame assembly (not shown). The rear suspension system 160 comprises of at least one rear suspension 160 preferably disposed centrally in the longitudinal mid plane of the vehicle 100. However, in a vehicle 100 with two rear suspensions, the same may be disposed on the left side and the right side respectively of the vehicle 100.
[00045] The first power source, for example the internal combustion engine 180 is mounted to a front lower portion of the frame assembly (not shown) by means of an engine mounting bracket (not shown). The internal combustion engine 180 is partially covered on the lower side of the internal combustion engine 180 by an engine cover 175. The internal combustion engine 180 is equipped with an exhaust system that includes an exhaust pipe connected to the internal combustion engine 180 and a muffler assembly 155 connected to the exhaust pipe. The muffler assembly 155 extends rearwards along the right side of the rear wheel 150.
[00046] Further, a swing arm 200 extending rearwards is swingably connected to a lower rear portion of the vehicle 100. The rear wheel 150 is rotatably supported at a rear end of the swing arm 200. Power from the internal combustion engine 180 is transmitted to the rear wheel 150 through a power drive mechanism, such as a drive chain, so as to drive and rotate the rear wheel 150. A center stand 165 is provided in between the front wheel 185 and the rear wheel 150 for parking the vehicle 100.
[00047] A rear fender 145 for covering an upper side of the rear wheel 150 is mounted to a rear portion of the vehicle 100 to prevent mud and water splashed by the rotating rear wheel 150 from entering the muffler assembly 155, the internal combustion engine 180 and other parts disposed close by. To enhance the overall aesthetics of the vehicle 100 and to prevent undesired foreign particles from entering parts of the vehicle 100, a plurality of rear covers (not labeled) is attached to a rear portion of the frame assembly (not shown).
[00048] Area below the seat assembly 125 and the fuel tank assembly 120 of the vehicle 100 is covered on both sides by a cover frame assembly 170. The cover frame assembly 170 includes the one or more side covers.
[00049] Fig. 2 illustrates a side perspective view of the internal combustion engine 180, according to an embodiment of the present subject matter. The internal combustion engine 180 includes a cylinder block 202 supported by a crankcase assembly 201 of the internal combustion engine 180. The cylinder block 202 defines a cylinder portion at which a piston can perform reciprocating motion. A cylinder head 203 is mounted to the cylinder block 202 and the cylinder head 203 acts as one end of the cylinder portion. The cylinder block 202 is provided with cooling fins 206 and the cylinder head 203 may be provided with the cooling fins.
[00050] The internal combustion engine 180 comprises a piston (not shown) performing a reciprocating motion in the cylinder portion due to force imparted to it by the combustion of air-fuel mixture. This reciprocating motion is converted and transferred to a rotary motion of a crankshaft 210 through a connecting rod (not shown). Further, a cylinder head-cover 204 is mounted to the cylinder head 203. The crankcase assembly 201 is made up of left-side crankcase and right-side crankcase. The crankcase assembly 201 rotatably supports the crankshaft 210. Further, an electric machine like a magneto assembly 211 or an integrated starter generator is mounted to the crankshaft 210. The magneto assembly 211 during operation is used to charge a battery (not shown).
[00051] The cylinder head 203 includes an intake port 205 and an exhaust port 208 (shown in Fig. 3a) that are provided on a first face and a second face of the cylinder head 203. In the present embodiment, the first face is an upward facing side and the second face is a downward facing side thereof. Further, the cylinder head 203 supports a camshaft assembly (not shown) that is capable of operating intake valve(s) and exhaust valve(s) of the internal combustion engine.
[00052] Fig. 3a to Fig. 3b illustrates a side perspective view of the internal combustion engine 180 elaborating the internal parts of the internal combustion engine 180, according to an embodiment of the present subject matter. Fig. 3b illustrates internal parts of the internal combustion engine 180 without a clutch assembly 207.
[00053] The internal combustion engine 180 includes a gear oil pump drive connected to the crankshaft 210 and rotates integrally with it. The oil pump drive gear includes a primary driving gear 213. The primary driving gear 213 acts a primary drive and is capable of transferring rotational force to a primary driven gear (not shown). The primary driven gear is thus operably connected to the crankshaft 210. The cylinder head 203 comprises a valve train arrangement to control opening and closing of intake and exhaust valves present at the intake port 205 (shown in Fig. 2) and exhaust ports 208 thereby controlling intake of air-fuel mixture and outlet of exhaust gases. The camshaft assembly (not shown) is rotatably mounted to the cylinder head 203 (shown in Fig. 2). A cam chain (not shown) operably connects the crankshaft 210 and camshaft assembly. A driven sprocket of the camshaft assembly is configured to be meshed with the primary driving gear 213 and the driven sprocket transfers the rotary motion of the crankshaft 210 to the camshaft assembly.
[00054] Typically, the transmission assembly of the internal combustion engine 180 includes a spring-loaded centrifugal clutch assembly 207 fixedly attached to the left-hand portion of the crankshaft 210 using plurality of fastening means. The right-hand side of the crankcase 201 encloses a dry magneto assembly 211. The dry magneto assembly 211 is configured to rotate along with the crankshaft 210 to generate power which recharges the battery (not shown). Further, as per an embodiment, a centrifugal fan (not shown) is disposed in front of the magneto assembly 211 forming part of a cooling system of the internal combustion engine 180 to cool the internal combustion engine 180. The centrifugal fan (not shown) rotates along with the crankshaft 210 and draws atmospheric air inside and circulates it throughout the interior portions of a shroud (not shown).
[00055] The clutch assembly 207 further includes one or more clutch plates 207a, a clutch hub 207b, and a flywheel (not shown). The clutch assembly 207 is fixedly attached by fastening means to an input shaft 209 (as shown in Fig. 3b). The clutch assembly 207 i.e. centrifugal clutch 207 ensures that at low to idle speeds the power transmission from the internal combustion engine 180 is disengaged to the rear wheel 150 (as shown in fig. 1) as spring loaded centrifugal shoe unit (not shown) fixedly attached to the left hand side of the crankshaft 210 and capable of expanding and engaging with a clutch drum (not shown) on rotation of the crankshaft 210 beyond a predetermined speed thereby rotating the driving gear 213 and a secondary driving gear.
[00056] During running of the vehicle 100 lot of heat is generated inside the internal combustion engine 180. For reducing the impact of the heat on the piston, the cylinder block 202 (shown in Fig. 2) and other engine parts, an oil sump 212 is provided in the crankcase 201 to store oil and collect the falling oil during normal operation to be cycled again through an oil drain plug 214. To retain that oil during normal operation within the internal combustion engine 180 a crankcase cover member (not shown) is provided comprising an oil seal housing to which an oil sealing assembly is attached.
[00057] Usually, the oil sump 212 is provided in the bottom-side of the left-hand side of the crankcase 201 for continuous lubrication and cooling of a piston and a plurality of piston cylinder wall and other parts of the internal combustion engine 180.
[00058] Fig. 4a to Fig. 4b illustrates exploded perspective views of the internal combustion engine 180 elaborating the internal parts of the internal combustion engine 180, according to an embodiment of the present subject matter. The lubrication and cooling of the piston, the plurality of piston cylinder wall and other parts of the internal combustion engine 180 begins once an operation cycle of thermal energy conversion into mechanical energy begins by means of a kick lever 217. Once the operation cycle starts, rotation of the crankshaft 210 also starts.
[00059] As per internal combustion engine 180 construction, on the left-hand side of the crankshaft 210, a gear oil pump drive is mounted through press-fitting process and the gear oil pump drive are mated with an oil pump assembly. The gear oil pump drive includes a primary driving gear 213, and a secondary driving gear 221. The oil pump assembly includes an oil pump cover assembly 220 and an oil pump 215. The gear oil pump drive and the oil pump assembly are assembled together on an oil pump shaft 216. Since the gear oil pump drive is placed is coupled to transfer torque from the crankshaft 210, the rotation of the crankshaft 210 initiates the starting of the gear oil pump drive along with the oil pump assembly. This ultimately results in the movement of lubricant oil 300 from an oil sump 212 of the internal combustion engine 180. Usually, a lubrication filter passage is connected to the lubrication passages from the oil sump 212 through a cross drill from a crankcase top surface of the internal combustion engine 180. The oil pump 215 pressurizes the lubrication oil 300 (shown in Fig 8b) present in the oil sump 212 and delivers the lubrication oil 300 to the oil filter pocket 233 (shown in Fig 9a) along a desired path provided in the crankcase 201.

[00060] The crankshaft 210 further includes a crankshaft bearing 219 disposed below the crankshaft 210.
[00061] Fig. 5 illustrates a perspective view of the inside portion of the internal combustion engine 180 while elaborating the internal parts of the internal combustion engine 180, according to an embodiment of the present subject matter. The present illustration illustrates a clutch assembly 207 housed in a clutch housing 207c. A clutch lever adjuster 222 is present upwardly of the clutch assembly 207 (shown in Fig 5 ). The clutch assembly 207 is enclosed in a cover clutch 207c. Adjacent to the cover clutch 207c an oil filter or strainer 223 is disposed, upon which an oil pump assembly including an oil pump 215 is disposed. A dipstick 224 is disposed in proximity of the oil filter or strainer 223 and the oil pump 215. A spark plug 225 is disposed above the magneto assembly 211 of the internal combustion engine 180 of the vehicle 100. The spark plug 225 acts as a device for delivering electric current from an ignition system to the combustion chamber of the internal combustion engine 180 to ignite the compressed fuel/air mixture by an electric spark, while containing combustion pressure within the internal combustion engine 180.
[00062] Fig. 6a and Fig. 6b illustrate a perspective exploded view and side perspective view respectively of the internal combustion engine 180 while elaborating the internal parts of the internal combustion engine 180, according to an embodiment of the present subject matter. To prevent that leakage from the internal combustion engine 180 a cover member (not shown) is provided with an oil seal housing (not shown) to accommodate an oil sealing assembly. The oil sealing assembly consists of a ring (not shown) as the inner skeleton which provides the structural stability to the oil sealing assembly and an outer skin part 227. The outer skin part includes one or more elastic member(s) 226. The one or more elastic member 226 of the oil sealing assembly tends to provide support to the outer skin part 227 and prevents lubricant oil from leaking outside and also prevents the entry of dirt, moisture and contaminants from outside. Also, the oil sealing assembly is designed in a manner that the oil sealing assembly retains the lubricant oil and pressure inside the internal combustion engine 180. Further, there is no provision to store lubricant oil for the lubrication and cooling of the oil sealing assembly.
[00063] Typically, the oil sealing assembly is first inserted into the oil seal housing before it is disposed over the gear oil pump drive and the oil pump 215 (shown in Fig. 5) along the oil pump cover assembly 220. The oil sealing assembly works by creating a thin layer of lubricant pressurized oil between the inner diametrical surface of the oil sealing assembly and the gear oil pump drive. Capillary action causes the oil to seep between the inner diametrical surface of the oil sealing assembly and the gear oil pump drive, which results in the oil wetting the inner diametrical surface of the oil sealing assembly clear of the gear oil pump drive. This thin layer is retained, and prevents leakage of lubricant oil through the inner diametrical surface of the oil sealing assembly. The oil sump 212 is a metal dish which covers the bottom of the cylinder block 202, and holds the engine oil when it is not circulating around the internal combustion engine 180.
[00064] Fig. 7 illustrates sectional views of the oil pump cover assembly 220 of an internal combustion engine 180, according to an embodiment of the present subject matter. The present illustration illustrates that an oil groove passage 230 (shown in Fig. 8c) and a first cross drilled passage 231 (shown in Fig. 8c) together forms a lubrication passage 232. The oil groove passage 230 of the lubrication passage 232 is cast on at least a portion of the crank case 201and lies in a region below a second plane LL (shown in Fig 8c), defined as a plane passing horizontal through a crankshaft axis (210). The second groove part 230a of the oil groove passage 230 is covered by means of a first groove part 230b, wherein the second groove part 230a is casted on an oil pump cover assembly 220. Furthermore, the first cross drilled passage 231 is operably connected on at least one end of said oil groove passage 230.
[00065] The oil pump cover assembly 220 further includes one or more pockets (228, 229) including an oil pump outlet pocket 228 and an oil pump inlet pocket 229, and an oil pump 215. At least one oil pump 215 is disposed at a bottom end of the internal combustion engine 180. Moreover, the second groove part 230a and thefirst groove part 230b lies in a first region A and the rest of the oil pump cover assembly 220 lies in a second region B. The first region A being a region of the oil pump cover assembly 220 extending outwardly beyond a plane MM. .The first region A and the second region B are separated by the first plane MM (marked by dotted line).
[00066] Fig. 8a to Fig. 8c illustrate a sectional and perspective view of the internal combustion engine 180 while elaborating the internal parts of the internal combustion engine 180, according to an embodiment of the present subject matter.
[00067] The internal combustion engine 180 comprises of at least one crankcase 201 portion, at least one crankshaft bearing 219, and at least one oil pump (215). At least one crankshaft bearing 219 aids in supporting the crankshaft 210 on at least one crankcase 201 portion of the internal combustion engine 180. The at least one crankcase 201 portion receives the crankshaft 210. The at least one oil pump 215 aids in supplying lubrication oil 300 from an oil sump 212 to other components of the internal combustion engine 180. The at least one oil pump 215 being disposed on the crankcase 201 substantially below the at least one crankshaft bearing 219.
[00068] One or more pockets (228, 229) are formed on the crankcase 201 for receiving the lubrication oil 300 from at least one driving gear (213, 221) (shown in Fig. 4a) of the at least one oil pump 215.
[00069] To overcome the problem related to long drilled passage, instead of drilled holes in crankcase 201, a casted groove is made in crankcase 201 that connects the oil pump outlet pocket 228 in the oil pump cover 220 and a single cross drill passage 231, herein called as a first cross drilled passage 228 is made in the crankcase 201 from the crankcase 201 top surface to casted groove, herein called as an oil groove passage 230. Therefore, the oil groove passage 230 and the single cross drill passage 231 together make a lubricating passage 232. The oil groove passage 230 includes a first groove part 230b and a second groove part 230a. The first groove part 230b is casted on the at least one crankcase 201. To cover the first groove part 230b in the crankcase 201, a matching groove is provided in the oil pump cover assembly 220. The oil groove passage 230 receives the lubrication oil 300 from the one or more pockets (228, 229) (shown in Fig. 7). The lubrication oil 300 from the oil pump 215 then flows through the first groove part 230b in the crankcase 201 and delivers to the cross drill made in the crankcase 201, i.e., to the single cross drill passage 231. And finally the lubrication oil 300 flows to the oil filter pocket 233 formed on the at least one crankcase 201 portion. . Hence, the intersection of machining drills is avoided by using a single drilled passage. Therefore, machining reduction and smooth flow of lubrication oil 300 from the oil pump 215 to the oil filter pocket 233 is achieved.
[00070] The oil filter pocket 233 is disposed on the cover clutch second part 207ccc (shown in Fig 9b) of the clutch assembly 207. The first cross drilled passage 231 allows lubrication oil to flow from the oil groove 230 to an oil filter pocket 233.
[00071] Further, as per the present embodiment, the crankshaft bearing 219 is disposed above the oil pump outlet pocket 228 and below the oil filter pocket 233 on the crankcase 201. As per the known art, providing a straight drilled hole from the top surface of the crankcase 201 leading to the oil pump outlet pocket 228 becomes non feasible, as it may interfere with the crankshaft bearing 219 and any such attempts would end up in weakening the strength of the bearing housing. Therefore, as per present invention, the oil groove passage 230 of the lubrication passage 232 lies in a region below a second plane LL (marked by a dotted line), such that the oil groove passage 230 bypasses the at least one crankshaft bearing 219. The first cross drilled passage 231 is drilled from top to bottom from the outer skin part 227 of the internal combustion engine 180 and lies in a region above the second plane LL.
[00072] Thus, the oil groove passage 230 provided by the present invention, helps in bypassing the crankshaft bearing 219and leads the lubricating oil 300 to the first cross drilled passage 231 connected at the end of the oil groove passage 230. Moreover, the first cross drilled passage 231 of the present invention is optimally formed to lead the lubricating passage232 to the oil filter pocket 233 on the crankcase 201. The low Length/Depth ratio of the first cross drilled passage 231 further ensures that the manufacturability of the first cross drilled passage 231 on the crankcase 201 is enhanced. Further, it also helps in increasing the drill tool life as the length of the first cross drilled passage 231 is optimal enough that would not lead to breakage of the drill tool during machining. As per an embodiment the lubricating passage 232 so formed by a combination of drilled passage 231 and an oil cast passage 230 has a Length / Depth ration for the drill portion in the range of 30:1 to 10:1
[00073] Fig. 9a and Fig. 9b illustrates parts of a clutch assembly 207 of an internal combustion engine 180, according to an embodiment of the present subject matter. The clutch assembly 207 is covered by a cover clutch 207c. The cover clutch 207c includes a cover clutch first part 207cc and a cover clutch second part 207ccc. An oil filter pocket 233 is disposed on the cover clutch second part 207ccc of the cover clutch 207c. Further the oil filter pocket 233 is disposed at an upper half of said crankcase 201, and wherein the oil filter pocket 233 is disposed substantially above the at least one crankshaft bearing 219 when viewed from a side of the internal combustion engine 180. The cross drilled passage 231 provided on at least one crankcase 201, is sealed on one end by an elastic member 226 (shown in Fig. 6a) of a cylinder block 202 of the internal combustion engine 180.
[00074] Many modifications and variations of the present subject matter are possible in the light of above disclosure. Therefore, within the scope of claims of the present subject matter, the present disclosure may be practiced other than as specifically described.

LIST OF REFERENCE NUMERAL
100 – Vehicle
105- Head lamp assembly
110- Head lamp
115- Handle bar assembly
120- Fuel tank assembly
120a: Down portion of fuel tank assembly
120b: Upper portion of fuel tank assembly
120c: Front portion of fuel tank assembly
120d: Rear portion of fuel tank assembly
125- Seat assembly
130- Tail cover assembly
135- Pillion handle
140a- Front indicator light
140b- Rear Indicator light
145- Rear fender
150- Rear wheel
155- Muffler assembly
160- Rear suspension system
165- Center stand
170- Cover frame assembly
175- Engine cover
180- Internal combustion engine
185- Front wheel
190- Front fender
195- Front suspension assembly
200- Swing arm
201- Crank case
202- Cylinder block
203- Cylinder head
204- Cylinder head cover
205- Intake port
206- Cooling fins
207- Clutch assembly
207a- Clutch plates
207b- Clutch hub
207c- Cover clutch
207cc- Cover clutch first part
207ccc- Cover clutch second part
208- Exhaust port
209- Input shaft
210- Crankshaft
211- Magneto assembly
212- Oil sump
213- Primary driving gear
214- Oil drain plug
215- Oil pump
216- Oil pump shaft
217- Kick lever
218- Stopper gear change lever
219- Crankshaft bearing
220- Oil pump cover assembly
221- Secondary driving gear
222- Clutch lever adjuster
223- Oil filter
224- Dipstick
225- Spark plug
226- Elastic member
227- Outer skin part
228- Oil pump outlet pocket
229- Oil pump inlet pocket
230- Oil grove passage
230a- Second groove part
230b- First groove part
231- First cross drilled passage
232- Lubricating passage
233- Oil filter pocket
300- Lubricating oil
MM- First plane
LL- Second plane
A - First region
B - Second region