FIELD OF INVENTION
[0001] The present invention relates to a cooling system for an engine and more particularly to a cooling system installed on the right side of the engine in a two-wheeled vehicle.
BACKGROUND OF INVENTION
[0002] In an internal combustion engine, combustion of fuel inside the cylinder, powers the transmission system along with production of a large amount of heat energy. This heat energy is mainly concentrated near the cylinder block and cylinder head of the internal combustion engine. Furthermore, it is very necessary to maintain the engine temperature at an optimum level to improve the combustion process. Thus, the heat generated in the cylinder block, which may be transmitted to the cylinder head, must be removed by using an external cooling system.
[0003] In such a vehicle with swinging engine,, a coolant circulated through cylinder block and cylinder head is used to extract the heat and thus cool down the engine. Different cooling system for extraction of heat from the internal combustion is possible. In such a two-wheeler, placing, locating and orientation of radiator becomes a great challenge due to space constraints. Placing a cooling system in such a two-wheeler in the front of the vehicle is not desirable, as it will lead to longer duct lengths. In addition, since on the left side, kick-starter is located, left side usage for cooling system mounting is also not desirable. Furthermore, an air filter, which is on left side of

the vehicle, shall be shielded from hot air coming through radiator; hence, radiator on the left side of the vehicle is also not desirable. Hence, there is a need to locate a radiator of a liquid cooled engine, which obviates the above-mentioned problems.
SUMMARY OF THE INVENTION
[0004] In order to obviate the limitations and the problems associated when the radiator is located in the front of the vehicle or on the left side of the vehicle, the current invention relates to providing a suitable location for cooling system on the right side of the engine. The vehicle right side being the right side of a rider when he is sitting on the vehicle while driving the vehicle.
[0005] The radiator in the current invention is placed between cover crankcase & radiator fan. The fan is axial - axial type in which the air is sucked by fan & passed through radiator. In the present invention, the two-wheeler engine has radiator on the engine right hand (RH) side. In the first embodiment of the current invention, the radiator is equipped with a slot in the middle through which an extended portion of crankshaft passes and to the end of the crankshaft, a radiator fan is bolted. The radiator is mounted on the crankcase cover by using fasteners. The radiator cover, which incorporates specially curved louvers for efficient entry of air, is mounted on the radiator.
[0006] In yet another second embodiment of the current invention, the two-wheeler engine has radiator on the engine right hand (RH) side and the radiator fan is mounted

on a mounting pad, which is integrated with the radiator cover. In such a cooling system, the engine size is compact & has less number of parts by having an axial fan compared to radial fan with shroud around the fan. In the current invention, no outlet passage is required as required in a centrifugal fan. In this second embodiment, the radiator fan is an electrical fan. The electrical fan can be electronically controlled based on engine rpm using electronic control unit.
[0007] Furthermore, we can program the input to the fan based on coolant passage temperature and avoid fan usage electronically by switching it on & off whenever ' required by using input from thermal sensor in the coolant passage. Installation of radiator in a two-wheeled vehicle on the right side of the engine also provides a better and efficient hot air exit from the engine cooling system.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 illustrates a typical type two-wheeler.
Figure 2 illustrates sectional view of a typical engine of a two-wheeler with radiator mounting according to first embodiment of the current invention.
Figure 3 illustrates isometric view of the cooling system according to second embodiment of the current invention.
Figure 4 illustrates sectional view of a typical engine of a two-wheeler with radiator mounting according to second embodiment of the current invention.

DETAILED DESCRIPTION OF THE INVENTION
[0008] The cooling system as disclosed in the current invention comprises of radiator mounting; radiator cover and its mounting, radiator cover profile, fan cover, and hot air vent through the fan cover as main elements. The current invention proposes a better and more efficient way of installing the radiator for a continuously variable transmission (CVT) type engine wherein the intake of fresh air for radiator cooling and exit of hot air through the integrated fan cover is described. The radiator & cover radiator is mounted together one above the other using four or three fasteners. The radiator, cover radiator are together assembled to fan cover. The fan cover is assembled to crankcase RH using four bolts. The radiator cap is protected against opening by an extension from cover for air ventilation. The cover air out has a mesh to avoid any solid particles going into the cowl. The coverair outlet is attached to cowl.
[0009] Figure 1 shows a typical two-wheeled vehicle 1 with a rear wheel 2, engine 3, air filter 4, front wheel 5, floorboard6, utility box 7, side panel 9, front shock absorber 10, rear shock absorber 11, grab rail 12, tail lamp 13 and rider seat 14. The direction of arrow "F' shows the front direction of the vehicle and direction of arrow "R" shows the rear direction of the vehicle. The engine 3as disclosed in Figure 1 produces heat energy after combustion of fuel inside it. The fuel is burnt inside the cylinder block and hence, the area near to cylinder block and the cylinder head get extensively heated up. The cylinder block and cylinder head area hence requires a supplementary cooling system to extract the heat thus generated.

[00010] Figure 2 shows a cylinder 21, connecting rod 22, crankshaft 23, one way clutch 24, magneto cover 25, cover oil pump 26, crankcase 27, radiator mounting 28, radiator 29, radiator cover mounting 30, crankshaft slot through radiator 31, radiator cover 32, air inlet 33 and crankshaft pin 34. LH denotes the left side of engine and RH denotes right side of the engine. The fuel burnt in cylinder 21 generates power, moves . connecting rod 22 and finally rotates crankshaft 23. In this process, the cylinder 21 attains a very high temperature. To reduce the temperature, a coolant duct is circulated through the cylinder 21's outer body. A radiator 29 is mounted on the crankcase 27. The crankshaft 23 is extended beyond the said radiator to accommodate a radiator fan 34. The radiator fan 34 being mounted through a mounting bolt 31 on the crankshaft 23. Further, in the current embodiment, the radiator cover 32 is mounted on the radiator 29 through mounting means.
[00011] When the engine 3 is switched ON, the crankshaft 23 starts rotating. Since the radiator fan 34 is mounted at one end of the crankshaft 23, the fan rotates, due to which atmospheric air is induced inside the radiator cover32. The radiator fan 34 draws atmospheric air inside the radiator cover 32 and expels along the dashed lines 36 shown in the Figure 2. This flow of air across the radiator 29 travelling through the path 36 cools down the radiator, ducts. The radiator ducts which carry coolant gets further cooled and thus thereby cooling the engine.
[00012] Figure 3 shows isometric view of yet another embodiment of the current invention with rear wheel 31, radiator cover 32, and a central longitudinal axis or a

vehicle horizontal axis 36; fan mounting pad 37 and radiator louvers 38. In this second embodiment, the radiator is mounted on the crankcase. The radiator cover is mounted on the radiator. The radiator fan is mounted on a mounting pad, which is integrated with the radiator cover. In this embodiment, the radiator fan 41, instead of being mounted on the crankshaft 23, is mounted on a fan pad. The fan pad as described above is mounted on a mounting pad, which is further integrated to the radiator cover 29.
[00013] For mounting the radiator fan 41 on the radiator cover 29, a cut-out section is integrated on the radiator louvers 38. The radiator fan 41 as disclosed in the current invention is preferably an electrically operated fan. In this second embodiment, electronic control unit depending upon the engine speed can control the rotational speed of the radiator fan 41. The radiator louvers 38 as shown in Figure 3 are designed in a manner so that the vanes are formed across a ripple direction from one corner to another corner in the diagonal direction.
[00014] Figure 4 shows engine 3 with radiator 29, radiator cover 32, radiator mounting 35 and radiator fan 41. As clearly shown in the Figure 4, the crankshaft ends before the radiator and does not stretch beyond or through the radiator. The radiator fan 34 in this embodiment is mounted on the radiator cover 32 with help of a mounting pad 37(as shown in Figure 3).

We claim:
1. A cooling system for a two-wheeler engine (3); the said cooling system comprising:
a radiator fan (34);
a radiator (29) wherein the said radiator (29) is mounted on a crankcase (27);
wherein the said radiator fan (34) is mounted on a crankshaft (23) of the said engine (3) by fastening means (31); the said radiator fan (34) along with the said radiator (29) being mounted on the right side.of the vehicle with respect to a central longitudinal axis (36).
.2. A cooling system for a two wheeler engine (3);; the said cooling system comprising:
a radiator fan (41);
a radiator (29) wherein the said radiator (29) is mounted on a crankcase (27);
wherein the said radiator fan (41) is mounted on mounting pad (37) of a radiator cover (32) on the said radiator (29); the said radiator fan (41) along with the said radiator (29) being mounted on the right side of the vehicle with respect to a central longitudinal axis (36).

3. The cooling system for a two-wheeler engine (3) as claimed in Claim 1 is equipped with radiator cover having circular rings (38) for trapping air and diverting towards the radiator.
4. The cooling system for a two-wheeler engine (3) as claimed in claim 1 wherein the radiator cover (32) is equipped with grills for stopping any foreign materials from entering the fan cover outlet.
5. The cooling system for a two-wheeler engine (3) as claimed in claim 1 wherein the mounting pad (37) being integrated with the radiator cover louvers (38).
6. The cooling system for a two-wheeler engine (3) as claimed in claim 2 wherein the radiator fan (41) is powered by electricity.