COOLING MECHANISM FOR POWER TRANSMISSION SYSTEM OF
A TWO WHEELED VEHICLE FIELD OF INVENTION
[0001] The present invention generally relates to power transmission system of a two wheeled vehicle and more particularly to cooling mechanism for said power transmission system of the vehicle.
BACKGROUND OF THE INVENTION
[0002] Generally, in two wheeled vehicles, especially in scooters using continuous variable transmission unit, a cover variator unit is used. The said variable transmission unit changes gear ratio at continuous intervals for efficient power transmission from crankshaft to clutch unit. This entire assembly is enclosed with a cover such that internal embodiments can be protected from foreign elements from the environment.
[0003] Due to friction between the clutch plates during power transmission and also due to mechanical operation of the variator, heat is generated in the transmission unit. As this unit is fully enclosed with mentioned cover, the generated heat is accumulated in it and cause damage to internal embodiments. [0004] To reduce the temperature of the transmission unit, an air inlet along with an outlet is commonly provided in the cover such that during movement of the vehicle air circulates in it and cools down the system. Along with the air, foreign elements from atmosphere like dust, mud and gravels etc. enters the transmission unit and harms the embodiments of the transmission unit.

SUMMARY OF THE INVENTION
[0005] Main objective of present invention is to provide a cooling mechanism for transmission unit for a two wheeled vehicle. For best depiction of the invention incorporation, a scooter with a continuously variable transmission (CVT) is taken for exemplary representation. However claimed mechanism can be applied or worked on any kind of transmission unit if required.
[0006] For this mechanism, a modified air cleaner is mounted above the transmission unit such that a secondary outlet from the air cleaner is connected to air inlet provided in the CVT cover. Said secondary outlet is facilitating air from air cleaner to the CVT unit and accommodates a secondary filter unit at minimum one end such that air without external elements like water, mud etc. does not get into CVT unit. Said secondary outlet is best suited to be in the dirty side of the air chamber however with suitable volume related improvements in the air cleaner this secondary outlet can be provided in clean side as well.
[0007] Summary provided above explains the basic features of the invention and does not limit the scope of the invention. Additional detailed information related to the enablement of the invention will be provided in the detailed description and accompanying claims. Scope of the invention shall be based on the claims provided.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0008] The present invention will become more fully understood from the detailed description given herein below and the accompanying drawing(s). Provided drawings are incorporated in and constitute embodiments of the

invention and illustrates several aspects of the invention and together with a
description of the embodiments serve to explain the principles of the invention.
Drawings given below are provided to support the description of the invention and
are not limiting the scope of the present invention. A brief description of the
drawing is as follows:
Figure 1 shows an exemplary two wheeled vehicle best suited for enablement of
the claimed invention.
Figure 2 and Figure 3 are depicting essential embodiments of the invention
describing mounting arrangement for the same.
Figure 4, Figure 5 and Figure 6 collectively depicts the enabling arrangement of
the embodiments of the claimed invention.
DETAILED DESCRIPTION OF THE INVENTION
[0009] The embodiments disclosed below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that best enabling arrangements of the invention can be explained through all possible embodiments and examples of it. The invention may have application to all kind of two wheeled vehicles.
[0010] Referring to Figure 1 shows a side view of a concerned two wheeled vehicle in the form of a scooter 100 capable to incorporate the present invention. Said scooter 100 has a front part 101 and a rear part 102 connected by a floor board 116 facilitating a leg space through the scooter 100. Front part of the vehicle supports a handle bar assembly 103 fixed with a front suspension unit 001.

Said front suspension unit 001 is fixed with the axle of the front wheel 107 and facilitates wheel clearance and acts as a damper at jolts while riding the scooter 100. Front part 101 of the scooter 100 is covered with a front panel 104 in order to accommodate embodiments mounted on the front part of the scooter 100 such as headlamp 105 in front and handle bar assembly 103 and front fork assembly 001 behind it. A front fender 106 is mounted over the front wheel 107 in order to protect front panel 104 and other embodiments from water and mud splash from front wheel 107 during scooter 100 movement.
[0011] Rear part 102 of the scooter 100 is covered with a rear panel 109 forming a housing space for embodiments like storage box, engine 117, battery etc. A seat 108 is accommodated above the rear panels 109 such that said storage box is accommodated below said seat 108. At the rearmost end of the scooter 100 and neighbouring the rear panel 109 and the seat 108, a pillion handle 110 and a tail lamp assembly 002 is fixed above a rear fender 111. Said rear fender 111 is covering the upper area of the rear wheel 113.
[0012] A transmission unit 114, continuous variable transmission unit (CVT unit) for most beneficial and best mode enablement of the invention, is connecting engine 117 output to the axle of the rear wheel 113 for scooter 100 movement. Generally, in scooters using continuous variable transmission 114 a cover variator unit (not shown in drawings) is used that changes gear ratio at continuous intervals for efficient power transmission from crankshaft to clutch unit (not shown in drawings). This entire transmission assembly 114 is enclosed with a

cover such that embodiments can be protected from foreign elements from the environment.
[0013] Due to friction between the clutch plates, during power transmission and also due to mechanical operation' of the cover variator heat is generated in the transmission unit 114. Increase in internal temperature of the transmission unit 114 affects the life of the transmission unit 114.
[0014] An air cleaner 112 is mounted above said transmission unit 114 and supplies air to the engine 117 as well as to the transmission unit 114. As shown in Figure 2 and Figure 3, air cleaner 112 has a primary outlet 118 facilitating air supply to the engine 117. A secondary outlet 115 from the air cleaner 114 is connecting it with the transmission unit 114 such that air 119-120 flows through the secondary outlet 115 and reaches to the transmission unit 114. [0015] As described in Figure 4, Figure 5 and Figure 6, air 124 enters the dirty side 112d of the air cleaner from the inlet 122. A portion 119 of the air 124 flows towards the secondary outlet 115 and remaining air flows towards the primary filter element 125 to enter the clean side 112c of the air cleaner 112. From clean side 112c of the air cleaner 112, air 114 flows to the engine 117 through the primary outlet 118. This primary outlet 118 is fitted with the air cleaner 112 though a removable linking mechanism 118b and with the engine through another removable linking mechanism 118a for the ease of serviceability of the air cleaner 112. For vehicle manufacturing requirement said primary outlet 118 can be made in any other configuration also e.g. as an integral part of air cleaner 112 or engine 117 as it suits.

[0016] For best enablement of the invention, said secondary outlet is the integral part of the air cleaner 112 and is connected with a removable fixing means with the transmission unit 114. Whereas, secondary outlet 115 can be made in any configuration with air cleaner 112 and transmission unit 114 e.g. it may be integrated with any of them and can be an independent embodiment as well. [0017] Further, air 119 entering into the secondary outlet 115, passes through a secondary filter element 123 such that any foreign particle such as oil, dust or water can be prohibited from entering the transmission unit 114. This secondary filter element 125 can be located at multiple locations depending on the vehicle requirement. Air 119 entering into the transmission unit 114 flows through it and exits through the outlet 120 provided at the rearmost end of the transmission unit 114.
[0018] Said secondary outlet 115 from the air cleaner 112 is best suited to be in the dirty side 112d of the air chamber however with suitable volume related improvements in the air cleaner 112 this secondary outlet 115 can be provided in clean side 112c as well.

WHAT IS CLAIMED IS
1) A two wheeled vehicle comprising a transmission unit transmitting power from and engine to a rear wheel such that a transmission cover is housing the transmission unit and an air cleaner mounted above the transmission unit and is connected to the engine through a primary outlet, characterized in that secondary outlet of the air cleaner is connected with an air inlet of the transmission cover, wherein the secondary outlet is facilitating air flow from air cleaner to the transmission unit.
2) The two wheeled vehicle, as claimed in claim 1, wherein, the secondary outlet has at least one secondary filter unit.
3) The two wheeled vehicle, as claimed in claim 1, wherein, the air cleaner defines a clean side and a dirty side such that the primary outlet is linked to the clean side.
4) The two wheeled vehicle, as claimed in claim 3, wherein, the secondary outlet is linked to the dirty side of the air cleaner.