TECHNICAL FIELD
[0001]' The present subject matter relates generally to an internal combustion engine for a two-wheeled vehicle. More particularly, the present subject matter relates to a bearing assembly for the internal combustion of the two-wheeled vehicle.
BACKGROUND
[0002] A conventional internal combustion engine converts chemical energy into mechanical energy by combustion of air-fuel mixture within a combustion chamber of the engine. The engine, among other components, has a cylinder on top of which a cylinder head is mounted, and receives a reciprocating piston from the bottom. On combustion of the air-fuel mixture, the piston transfers the energy generated during combustion to a crankshaft through a connecting rod thereby driving the crankshaft. In this way, the reciprocatory motion of the piston is converted to rotary motion of the crankshaft. The crankshaft rotation then powers the vehicle.
[0003] Operation of such conventionaL engines generates noise, vibrations, and other internal forces due to reciprocating masses. In order to cancel out vibrations and other internal forces, a plurality of counter weights are generally used, such counterweights being arranged within the crankcase. Similarly, in order to cancel out noise emanating out of the engine, more particularly that of bearing noise that is more predominant due to radial clearance of the bearing and fit between the bearing OD and crankcase housing ID, which controls the radial and axial movement of the bearing, conventional engine arrangements involved optimizing

the bearing fit on crankshaft and crankcase. However, such an optimization has no impact in the overall reduction of engine noise, if the problem relating to thermal expansion between crankcase housing and bearing is not addressed, as such thermal expansion may lead to increase in clearance between mating parts.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to reference like features and components.
[0005] Fig. 1 shows a side view of a two-wheeled motorcycle 100.
[0006] Fig. 2 shows a cross-sectional view of an internal combustion engine 113 of the two-wheeled vehicle 100.
[0007] Fig. 3 (a) shows a cross-sectional view of a bearing assembly 300 of the internal combustion engine, in accordance with a first embodiment of the present subject matter.
[0008] Fig. 3 (b) shows an exploded view of the bearing assembly 300 of the internal combustion engine 113 of the two-wheeled vehicle 100, in accordance with a first embodiment of the present subject matter.
[0009] Fig. 4 (a) shows a perspective view of a dampener member 308 of the bearing assembly 300 of the internal combustion engine 113, in accordance with an embodiment of the present subject matter.

[00010] Fig, 4 (b) shows a top view of the dampener member 308 of the bearing assembly 300 of the internal combustion engine 113, in accordance with an embodiment of the present subject matter.
DETAILED DESCRIPTION
[00011] Almost all conventional, engines used in two-wheeled vehicles are cranked using a kick-start mechanism, while the rest of the engines are cranked using both kick-start mechanism and electric starter mechanism. There is an. ever-increasing demand for engines that produces less noise, less vibration, and less internal forces combined with reduced weight and enhanced fuel efficiency.
[00012] Conventionally, internal combustion engine assembly includes a crankcase, a cylinder block coupled to the crankcase, and a cylinder head mounted on the upper part of the cylinder block. A reciprocating piston that is slidably fitted in the cylinder block is connected via a connecting rod to a crankshaft. The crankshaft that is rotatably supported by the crankcase includes a crankshaft inner diameter and a crankshaft web outer diameter on LH side and RH side of the centrally disposed connecting rod. Generally, the LH and RH crankshaft drives a plurality of gears to operate one or more systems of the internal combustion engine. .
[00013] Furthermore, the operation of various gears in tandem with each other causes unwanted noise within a transmission assembly of the IC engine: The production of such noise is attributed to an unwanted characteristic exhibited by the gears. In addition to such noise generated by the plurality of gears, noise is

also generated by other parts of the engine. For example, one or more primary bearings are disposed between the rotating crankshaft assembly and the crankcase of the engine. Such primary bearing assemblies tends to rotate along with the crankshaft substantially at a similar speed as that of the crankshaft. Under most circumstances, such a rotation of the primary bearing assemblies may cause the outer diameter of the primary bearing assemblies to establish contact with an inner diameter of the crankcase that is disposed circumferentially outsider the outer diameter of the primary bearing assembly.
[00014] High-speed rotation of the primary bearing assemblies combined with the contact made between the outer diameter of the primary bearing assembly and the inner diameter of the crankcase tends to generate noise, which causes an unpleasant driving experience to the rider of the two-wheeled vehicle. In addition to generation of unpleasant engine noise, the contact established between the outer diameter of the primary bearing assembly and the inner diameter of the crankcase causes one of the part to wear out and often may lead to both the parts wearing out much earlier than the otherwise expected life time of these parts. In case of the wearing out of the inner diameter of the crankcase, the entire LH side or RH side crankcase has to be replaced to prevent having any deterrent effect on the overall functioning of the engine. Moreover, under most circumstances, noise emanating due to wearing out of one of the primary bearing assemblies often lead to changing of both the LH and RH primary bearing assemblies.
[00015] The present subject matter is aimed at solving the problems posed by the conventional internal combustion engine assembly. The present subject matter

provides a bearing assembly for an internal combustion engine assembly of a two-wheeled vehicle that eliminates noise emanating out of working of one or more components of the bearing assembly of the internal combustion engine. In an embodiment, the present subject matter provides an internal combustion engine assembly with an improved bearing assembly having a dampener member that enables the bearing assembly of the present subject matter to overcome the problems associated with the bearing assemblies of the conventional internal combustion engines.
[00016] In an embodiment, the dampener member of the present subject matter is assembled at least between an inner diameter of crankcase housing and an outer diameter of one of the bearing element. Moreover, in one embodiment, the dampener member is provided with plurality of corrugations on its outer surface, which enables the dampener member to act as a spring and effect dampening of radial movement of the bearing element due to increase in clearance in radial direction. Such a dampener member of the present subject matter enables effective reduction of noise and vibration of the engine. In another embodiment, the outer and inner surfaces of the dampener member are provided plurality of corrugations that enables the dampener member to achieve necessary characteristics of a spring.
[00017] In one embodiment, the dampener member is provided with a geometrical profile including square or triangular profile. The dampener member is assembled in between the crankcase housing inner diameter, which is a cylindrical surface, and the outer diameter of the bearing element, which is a

cylindrical surface, on either side, i.e., on LH and RH sides of the crankshaft assembly. The dampener member provided on either side of the crankshaft assembly of the present subject matter enables effective reduction of noise and vibration. In one embodiment, the dampener member acts as a radial spring, thereby improving the noise and vibration characteristics of the engine by constraining the radial movement of the bearing element. Further, in another embodiment, the dampener member prevents thermal expansion between the. mating parts, i.e., between the outer diameter of the bearing element and the inner diameter of the crankcase housing inner diameter, under all ranges of temperatures, and especially ranging from 30° C to 140° C.
[00018] In one embodiment, the dampener member is made of a metallic member establishing the required characteristics of preventing wear of adjoining components, acting as. a spring, and thermal resistant can be used. For instance, spring steel cm be effectively used as a dampener member. Similarly, any well-known non-metallic polymer material that establishes similar characteristics can be used as material for the dampener member. For example, non-metallic polymer such as Teflon can be used as a material for the dampener member. In an embodiment, the dampener member can range between 1.5 mm to 5 mm of thickness to establish desired characteristics as explained above. In one embodiment, the dampener member includes a collar that enables prevention of axial movement of the dampener member. In an embodiment, the primary bearing element of the crankshaft assembly is a ball bearing. In another embodiment, the

primary bearing element of the crankshaft assembly can be a cylindrical roller bearing.
[00019] These and other advantages of the present subject matter would be described in greater detail in conjunction with the figures in the following description.
[00020] Fig. 1 illustrates a side view of a two-wheeled vehicle, for example, a motorcycle 1 according to an embodiment. The motorcycle 1 according to an embodiment includes a front wheel 101 steered by a handlebar 102 and a rear wheel 103 supported by a swing arm 104. Steering system parts including the handlebar 102 and the front wheel 101 are supported for pivotal steering operation on a head pipe 105 at the front end of the vehicle body frame 106. A seat 110 for a driver and a pillion is placed rearward to a fuel tank 114. An engine assembly 113 is disposed below the fuel tank. A front fender 111 is provided above the front wheel 101. to avoid the said vehicle and its occupants from being splashed with mud. Likewise, a rear fender 112 is placed above the rear wheel 103, and to the outer side in the radial direction of rear wheel 103. Rear fender 112 inhibits rainwater or the like from being thrown up by rear wheel 103.
[00021] The swing arm 104 along with a shock absorber 109 is supported at a rear portion thereof for pivotal motion and upward and downward rocking motion on the rear side of a lower portion of the vehicle body frame 106. A suspension system including a pair of front forks 108 and the shock absorber 109 is provided in the two-wheeled vehicle 1 for providing better ride comfort to the rider. In general terms, the shock absorbers help cushion vehicles on uneven roads. In the

two-wheeled vehicle, shock absorbers reduce the effect of traveling over rough ground, leading to improved ride quality and vehicle handling.
[00022] The vehicle body frame 106 includes the head pipe 105, a pair of left and right main frames 107. The head pipe 105 is positioned at a front-end portion of the vehicle body frame 106. The main frames 107 extend in a leftwardly and rightwardly branching state obliquely downwardly rearwardly from a lower portion of the head pipe 105.
[00023] Fig. 2 shows a cross-sectional view of an internal combustion engine 113 of the two-wheeled vehicle 100. In an embodiment, rotation of a connecting rod 212 connects a piston (not shown in Fig 2) of the IC engine 113 with a crankshaft through a bearing (not shown in Fig 2). A primary drive gear 214 is operably connected to the crankshaft and rotates with the speed of rotation of the crankshaft. The connecting rod 212 transfers, the motion of the piston to the crankshaft by way of conversion of the reciprocating motion of the piston into rotary motion of the crankshaft. The primary drive gear 214 acts as a motion transmitting means to facilitate transmission of the rotary motion of the crankshaft to a drive-train system (not shown in Fig 2) and to various other components of the IC engine 113 through a primary driven gear 216.
[00024] Further, in one embodiment, a balancer drive gear 222 meshes with the primary drive gear 214, which in turn transmits motion to a balancer driven gear 218. In an embodiment, the balancer drive gear 222 is rotated at the speed of rotation of the crankshaft. Further, in one embodiment, the primary gear drive 214

meshes with an oil pump drive gear 224 that enables operation of oil pump by transfer of motion through an oil pump driven gear (not shown in Fig.2).
[00025] Fig. 3 (a) shows a cross-sectional view of a bearing assembly 300 of the internal combustion engine 113 of the two-wheeled vehicle 100, in accordance with a first embodiment of the present subject matter. In an embodiment, the motion of the connecting rod 212 causes the crankshaft assembly 204 to rotate. In an embodiment, left and right bearing elements 306-1, 306-2 are circumferentially disposed around the crankshaft assembly 204 in such a manner that the left bearing element 306-1 is held against a left side crankshaft web 206-1, while the right bearing element 306-2 is held against a right side crankshaft web 206-2. Thus, rotation of the crankshaft assembly 204 causes a corresponding rotation of the left and right bearing elements 306-1, 306-2.
[00026] In an embodiment, the crankshaft assembly 204 adjoining the left bearing element 306-1 extends leftwardly through a crankcase housing LH 302, in such a manner that the inner diameter (not shown) of the crankcase housing LH 302 is disposed enveloping the left bearing element 306-1. Similarly, the crankshaft assembly 204 adjoining the right bearing element 306-2 extends rightwardly through a crankcase housing RH 304, in such a manner that the inner diameter (not shown) of the crankcase housing RH 304 is disposed enveloping the right bearing element 306-2.
[00027] In an embodiment, the contact between the outer diameter of the left bearing element 306-1 and the inner diameter of the crankcase housing LH 302 can be eliminated by accommodating a left dampener member 308-1. Similarly,

the contact between the outer diameter of the right bearing element 306-2 and the inner diameter of the crankcase housing RH 304 can be eliminated by accommodating a right dampener member 308-2.
[00028] Fig. 3 (b) shows an exploded view of the bearing assembly 300 of the internal combustion engine 113 of the two-wheeled vehicle 100, in accordance with a first embodiment of the present subject matter. In an embodiment, the crankcase housing LH 302 includes an inner diameter 310 that accommodates the left bearing element 306-1. In an embodiment, the left dampener member 308-1 is disposed between the inner diameter 310 of the crankcase housing LH 302 and the outer diameter of the left bearing element 306-1. Similarly, the right dampener member 308-1 (not shown) is disposed between the inner diameter (not shown) of the crankcase housing RH (not shown) and the outer diameter of the right bearing element 306-2.
[00029] Fig. 4 (a) shows a perspective view of a dampener member 308 of the bearing assembly 300 of the internal combustion engine 113, in accordance with an embodiment of the present subject matter.
[00030] Similarly, Fig. 4 (b) shows a top view of the dampener member 308 of the bearing assembly 300 of the internal combustion engine 113, in accordance with an embodiment of the present subject matter. In an embodiment, the dampener member 308, i.e., both the left dampener member 308-1 and the right dampener member 308-2 has a corrugated profile. In one embodiment, the dampener member 308 includes an outer surface 404, and an inner surface 402. Further, in an embodiment, the dampener member 308 is ring shaped, and at least

one end of the ring shaped dampener member 308 includes a collar 406 that is perpendicularly and inwardly disposed, which is extending in a radially inward direction, to at least one end of the dampener member 308.
[00031] In an embodiment, the inwardly extending collar 406 enables prevention of axial movement of the dampener member 308. Further, in one embodiment, the outer surface 404 of the dampener member 308 has a plurality of alternatively disposed depressions 410 and projections 408. In an embodiment, the plurality of alternatively disposed depressions 410 and the projections 408 extends throughout the circumference of the outer surface 404 of the dampener member 308.
[00032] In an embodiment, the plurality of alternatively disposed depressions 410 and the projections 408 enables the dampener member 308 to act as a spring and simultaneously ensuring that any thermal expansion that may occur between the mating parts, i.e., the inner diameter 310 of the crankcase housing 302, 304 and the outer surface 404 of the dampener member 308 is eliminated. In one embodiment, the outer surface 404 of the dampener member 308 has a triangular profile. In another embodiment, the outer surface 404 of the dampener member 308 has a square profile.
[00033] It is to be understood that the aspects of the embodiments are not necessarily limited to the features described herein. 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.

I/We claim:
1. An internal combustion engine assembly (113) for a vehicle (100), said internal combustion engine assembly (113) comprising:
a piston (205) having a reciprocating motion in a cylinder;
a crankshaft assembly (204) connected to said piston (205) through a connecting rod (212), said crankshaft assembly (204), comprises one or more crankshaft web(s) (206-1, 206-2);
one or more bearing element(s) (306-1, 306-2) are circumferentially disposed around the crankshaft assembly (204), said bearing element(s) (306-1, 306-2) are held against said crankshaft web(s) (206-1, 206-2); and
a crankcase housing LH (302) comprises an inner diameter (310) disposed enveloping a left bearing element (306-1) of the one or more bearing elements (306-1, 306-2), and a crankcase housing RH (304) comprises an inner diameter (310) disposed enveloping a right bearing element (306-2) of the one or more bearing elements (306-1, 306-2),
r
wherein .•■■-•'
said internal combustion engine assembly (113) further comprises a left dampener member (308-1) disposed between said inner diameter (310) of the crankcase housing LH (302) and an outer diameter of said left bearing element (306-1), and a right dampener member (308-2) disposed between said inner diameter (310) of the crankcase housing RH (304) and an outer diameter of said right bearing

0
element (306-2), and wherein said dampener members (308-1, 308-2) includes a corrugated profile.
2. The engine assembly (113) of claim 1, wherein said dampener member (308) includes a collar (406) that is perpendicularly and inwardly disposed in a radial direction to at least one end of said dampener member (308).
3. The engine assembly (113) of claim 1, wherein said dampener member (308) includes a plurality of depressions (410) and a plurality of projections (408) that are alternatively disposed throughout a circumference (402, 404) of the dampener member (308) forming said corrugated profile.
4. The engine assembly (113) of claim 1, wherein said circumference (402, 404) of the dampener members (308) comprises of a geometrical profile including square profile and triangular profile and said dampener member (308) has a thickness in range of 1.5 to 5 millimeters.
5. The engine assembly (113) of claim 1, wherein said dampener member (308-1, 308-2) has ring shape and said dampener member (308) envelops at least a portion of said bearing elements (306-1, 306-2).
6. The engine assembly (113) of claim 1 or 3, wherein said dampener member (308) includes an inner surface (402) and an outer surface (404) that form said circumference (402, 404).
7. The engine assembly (113) of claim 1, wherein said dampener member (308) is adapted to reduce thermal expansion between the bearing element (306-1, 306-2) and the inner diameter (310) of the crankcase housing (302, 304), in the range of 30° C to 140° C of temperature.

8. The engine assembly (113) of claim 1, wherein said dampener member (308) constrains radial movement of said bearing elements (306-1, 306-2) whereby said dampener member (308) acts as radial spring.
9. The engine assembly (113) of claim 1, wherein said inner diameter (310) of said crankcase housing LH (302) and said crankcase housing RH (304) are adapted to accommodate and support said dampener member (308).
10. The engine assembly (113) of claim 1, wherein said dampener member (308) is made of a non-metallic polymer.