Technical Field
[0001] The present subject matter described herein relates to a
clutch assembly for a two wheeled vehicle.
Background
[0002] Typically, a clutch assembly serves as a drive connection
between an internal combustion engine and a transmission system of a
two wheeled vehicle, said transmission system including the clutch
assembly among other components. Particularly, the clutch assembly
through a clutch shaft serves to transmit power from a crankshaft of the
internal combustion engine to a driveshaft of the transmission system.
Conventionally, the clutch shaft is rotatably coupled at one end to a clutch
hub of the clutch assembly and to a gearbox assembly at the other end.
Torque exerted to couple said clutch shaft to the clutch hub generates
axial load on the clutch shaft. Moreover, since the gearbox assembly
comprising secondary gears is also mounted to the clutch shaft, there is a
need to prevent axial load from getting transferred through the clutch shaft
to the gearbox assembly.
[0003] A conventional design of a device in a conventional clutch
assembly used for preventing transfer of axial load to the gearbox
assembly necessitated the device to be made of a low hardness material.
Moreover, the conventional design of the device, and the use of a low
hardness material for the same also did not permit heat treatment of the
device, thereby causing the same to yield and resulting in the failure of the

same. Therefore, failure of the device resulted in greater float around the
clutch shaft resulting in clutch noise and vibrations.
[0004] There is therefore a need for a clutch assembly which
' addresses problems associated with the conventional clutch assembly. Summary of the invention
[0005] The present invention has been made in view of the above
circumstances.
[0006] It is an object of the present invention to provide a clutch
assembly including a stopper unit for preventing axial load from getting transferred to a gearbox assembly..
[0007] It is another object of the present invention to provide a
clutch assembly including a stopper unit made of a rigid material.
[0008] It is yet another object of the present invention to provide a
clutch assembly including a stopper unit that aids in maintaining optimal clutch float around a clutch shaft, and thereby prevents generation of clutch noise and vibrations.
[0009] With the above and other objects in view, the present
invention provides a clutch assembly that through a clutch shaft transmits rotational energy from a crankshaft of the internal combustion engine to a driveshaft of said internal combustion engine. The clutch shaft rotatably coupled at its one end to a clutch plate sub assembly of said clutch assembly is subject to axial load as a result of torque applied for said coupling.

[0010] The present invention provides a clutch assembly including a
stopper unit, said stopper unit including a stopper plate and a stopper
washer adapted to be detachably attached to each other, and said stopper
unit being circumferentially disposed around at least a portion of the clutch
shaft. Particularly, the stopper unit including the stopper plate and the
stopper washer, which is adapted to be circumferentially disposed around
at least a portion of the clutch shaft; is seated on a slot formed in said
clutch shaft. Particularly, the stopper washer is adapted to be engaged
with said stopper plate, in a manner so as to arrest axial rotation of the
stopper plate around the clutch shaft. As per an embodiment of the
present invention, the stopper plate is provided with a plurality of pips to
receive said stopper washer, and the stopper washer in turn is provided
with a plurality of pip holes to receive said plurality of pips.
[0011] According to an aspect of the present invention, the stopper
washer is made of a rigid material such as spring steel. The use of a rigid material for the stopper washer permits the stopper washer to be broached for the formation of the plurality of pip holes therein. Moreover, the use of a rigid material such as spring steel allows the stopper washer to be heat treated so as to secure the same from yielding, thereby ensuring that the stopper washer reliably prevents axial rotation of the stopper plate without yielding. Further, proper seating of the stopper unit on the slot formed in the clutch shaft ensures that optimal float is

maintained around the clutch shaft, thereby preventing generation of
clutch noise and vibrations.
[0012] Summary provided above explains the basic features of the
invention and does not limit the scope of the invention. The nature and
further characteristic features of the present invention will be made clearer
from the following descriptions made with reference to the accompanying
drawings.
Brief Description of Drawings
[0013] The above and other features, aspects, and advantages of
the subject matter will be better understood with regard to the following
description and accompanying drawings where:
[0014] FIG-1 is a cross sectional view of an internal combustion
engine of a two wheeled vehicle.
[0015] FIG.2 is an exploded view of a clutch assembly of said
internal combustion engine depicting a stopper unit in accordance with, an
embodiment of the present invention.
[0016] FIG.3 is a perspective view of a stopper plate of the stopper
unit in accordance with an embodiment of the present invention.
[0017] FIG.4 is a perspective view of a stopper washer of the
stopper unit in accordance with an embodiment of the present invention.
Detailed Description of the Preferred Embodiments
[0018] The present subject matter described herein relates to a
clutch assembly for an internal combustion engine of a two wheeled

vehicle, and particularly relates to a stopper unit of said clutch assembly.
Exemplary embodiments detailing features of the clutch assembly, in
accordance with the present invention 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. Further, it is to be noted that
although the present invention has been exemplified for an internal
combustion engine of a two wheeled vehicle, the present disclosure is
applicable to internal combustion engine of all vehicles.
[0019] FIG-1 is a cross sectional view of an internal combustion
engine 10 of a two wheeled vehicle taken along cylinder centreline.
[0020] As may be seen, the internal combustion engine 10 includes
a crankshaft 11 rotatably supported in a crankcase 12. Reciprocating motion of a connecting rod 13 disposed inside a cylinder block (not shown) is converted into rotary motion by the crankshaft 11 for powering the internal combustion engine 10- Power thus generated in the cylinder block is transmitted to a rear wheel (not shown) through a transmission system including the clutch assembly 15. The clutch assembly 15 serves to control transmission of power. The internal combustion engine 10 includes a centrifugal filter assembly 14 mounted on the crankshaft 11 and a clutch assembly 15 mounted to a clutch shaft 17, said clutch shaft 17 being disposed parallel to the crankshaft 11. The clutch assembly 15 serves to engage or disengage with said clutch shaft 17.. Further, a driveshaft 19 is

mounted parallel to the clutch shaft 17 in the crankcase 12. The driveshaft
19 has a plurality of secondary driven gear(s) and a sprocket drive to .
transmit power to a rear wheel of the two wheeled vehicle.
[0021] Particularly, the clutch shaft 17 serves as an input shaft and
transmits power from the crankshaft 11 to the driveshaft 19 through a gearbox assembly 16 operatively connected to the clutch shaft 17 and disposed on one side of said clutch shaft 17.
[0022] The clutch shaft 17 is rotatably coupled to a clutch plate sub
assembly 15bh of the clutch assembly 15 at its one end, and is rotatably
coupled to the crankcase 12 at its other end. Further, said clutch plate sub
assembly 15bh including a plurality of clutch plates stacked next to each
other is housed in a clutch housing sub assembly 15be. The clutch
housing sub assembly 15be is adapted to freely rotate over a spacer 15bs
(shown in FIG.2) disposed over the clutch shaft 17. A torque applied to
couple said clutch shaft 17 to the clutch plate sub assembly 15bh causes
axial loading on the clutch shaft 17. Therefore, in order to prevent axial
load from getting transferred to the gearbox assembly 16, a stopper unit
18 is circumferentially disposed around the clutch shaft 17 in accordance
with an embodiment of the present invention. Thus, the stopper unit 18
serves as a load bearing member of the clutch assembly 15.
[0023] FIG.2 is an exploded view of the clutch assembly 15 in
accordance with an embodiment of the present invention. As may be seen, the clutch shaft 17 is rotatably coupled to a clutch plate sub

assembly 15bh by means of a clutch hut 15bd. Particularly, the clutch plate sub assembly 15bh comprises a central splined aperture 15bhc for receiving the clutch.shaft 17. When a rider shifts gears by operating a clutch lever (not shown), the clutch housing sub assembly 15be gets disengaged from the clutch plate sub assembly 15bh, facilitating gear shifting. An operating gap gets maintained automatically between each clutch plate of said plurality of clutch plates when the clutch lever is operated, thereby disengaging the clutch assembly 15 from the clutch shaft 17. The engagement-disengagement of the clutch assembly 15 around the clutch shaft 17 also exerts axial load on the clutch shaft 17, thereby necessitating the presence of the stopper unit 18 for preventing axial load from getting transferred to the gearbox assembly 16 disposed on one side of the clutch shaft 17.
[0024] In accordance with an embodiment of the present invention,
the stopper unit 18 including a stopper plate 18a and a stopper washer 18b is circumferentially disposed around the clutch shaft 17. Particularly, the stopper plate 18a and the stopper washer 18b is disposed in this order from a right side, over a slot 17a formed in the.clutch shaft 17. As may be seen, since the stopper unit 18 is disposed immediately ahead of the gearbox assembly 16 on the clutch shaft 17, the stopper unit 18 aids in arresting substantial amount of axial load from getting transferred to the gearbox assembly 16.

[0025] FIG.3 and FIG.4 illustrate constructional details of the
stopper plate 18a and the stopper washer 18b respectively.
[0026] FIG.3 is a perspective view of the stopper plate 18a as per
an embodiment of the present invention. As may be seen, the stopper plate 18a is a spherical member having an inner diameter 18ad which is splined. The inner diameter 18ad includes a plurality of plate crests 18aa and a plurality of plate troughs 18ab disposed alternatingly with respect to each other, and enable the stopper plate 18a to be easily inserted through said clutch shaft 17, said clutch shaft 17 integrally including a plurality of spline crests 17bc (shown in FIG.2), and a plurality of spline troughs 17bd . (shown in FIG.2); said plurality of spline crests 17bc and said plurality of spline troughs 17bd being formed alternatingly with each other on an outer circumference of said clutch shaft 17.
[0027] Further, the stopper plate 18a is provided with a plurality of
pips 18ac to receive the stopper washer 18b. For ease of assembly, the plurality of pips 18ac may be provided on both sides of said stopper plate 18a. Preferably, the plurality of pips 18ac may be provided corresponding to the plurality of plate crests 18aa on a plate surface 18ra of the stopper plate 18a. Alternately, the plurality of pips 18ac may be provided corresponding to the plurality of plate troughs 18ab on the plate surface 18ra of the stopper plate 18a.
[0028] The stopper plate 18a having the above mentioned details
when inserted individually through the clutch shaft 17 and located on the

slot 17a, is capable of rotation on the clutch shaft 17. The stopper plate 18a thus inserted through the clutch shaft 17 should be given a rotation so that said plurality of plate troughs 18ab get located against each spline crest face of the plurality of spline crests 17bc, so that when the stopper washer 18b is assembled on the clutch shaft 17, rotation of the stopper plate 18a is completely arrested. Thus, the stopper washer 18b (shown in FIG.4) inserted through the clutch shaft 17, and adapted to be engaged with the stopper plate 18a aids in arresting the axial rotation of the stopper plate 18a.
[0029] FIG.4 is a perspective view of the stopper washer 18b as per
an embodiment of the present invention. As may.be seen, the stopper washer 18b like the stopper plate 18a is also a spherical member having an internal diameter 18bd which is splined. The internal diameter 18bd of the stopper washer 18b includes a plurality of washer crests 18ba and a plurality of washer troughs 18bb disposed alternatingly with respect to each other. Further, the stopper washer 18b is provided with a plurality of pip holes 18bc to receive the plurality of pips 18ac of the stopper plate 18a. Preferably, the plurality of pip holes 18bc is formed on a washer surface 18rb of the stopper washer 18b in a manner such that it corresponds either to the plurality of washer crests 18ba or to the plurality of washer troughs 18bb depending on a location of the plurality of pips on the stopper plate 18a. For example, if the plurality of pips 18ac is located corresponding to the plurality of plate crests 18aa, then the plurality of pip

holes 18bc is located corresponding to the plurality of washer troughs 18bb, thereby allowing the plurality of plate crests 18aa to overlap with the plurality of washer troughs 18bb5 and overlap of the plurality of plate troughs 18ab with the plurality of washer crests 18ba in an assembled condition. Since the plurality of plate troughs 18ab is already located against the plurality of spline crests 17bc, assembly of the stopper washer 18b to mate with the stopper plate 18a causes the plurality of washer troughs 18bb to get locked between the plurality of spline crests 17bc, and therefore causing the complete stopper unit 18 to fixedly engaged on the clutch shaft 17. Thus, the axial rotation of the stopper unit 18 on the clutch shaft 17 is prevented. Specially, fixed engagement of the stopper unit 18 on the clutch shaft 17 enables the stopper unit 18 to take in the axial load getting transferred from the clutch plate sub assembly 18bh. Thus, a manner of disposition of the plurality of pip holes 18bc on the stopper washer 18b and its attachment with the plurality of pips 18ac on the stopper plate 18a in accordance with the present embodiment aids in arresting the axial rotation of the stopper plate 18a around the clutch shaft 17.
[0030] Particularly, as per an embodiment of the present invention,
the stopper washer 18b is made of a rigid material, for example spring steel. Use of spring steel for the stopper washer 18b permits broaching/punching to be performed for the formation of the plurality of pip holes 18bc therein. Moreover, use of spring steel also permits heat

treatmenVof the stopper washer 18b, thus enhancing the strength of the stopper washer 18b and securing the same from yielding due to the axial load. Further, the stopper plate 18a is also made of a rigid material. Thus, the stopper unit 18 including the stopper plate 18a and the stopper washer 18b functions to take in the axial load exerted on the clutch shaft 17 and prevents the same from being transferred to the gearbox assembly 16. Additionally, the disposition of the stopper unit 18 on the clutch shaft 17 also aids in maintaining an optimal float around the clutch shaft, thereby eliminating clutch vibrations and clutch noise.
[0031] While the present invention has been shown and described
with reference to the foregoing preferred embodiments, it will be apparent
to those skilled in the art that changes in form, connection, and detail may
be made therein without departing from the spirit and scope of the
invention as defined in the appended claims.

WeClaini:
1. An internal combustion engine (10) for a two wheeled vehicle,
wherein the internal combustion engine (10) includes a crankshaft
(11), a clutch shaft (17), a clutch assembly (15) comprising: a clutch
housing sub assembly (15be) and a clutch plate sub assembly
(15bh), said clutch assembly (15) being rotatably coupled to the
clutch shaft (17) and disposed on one side of the clutch shaft (17),
and a gearbox assembly (16) operatively coupled to the clutch shaft
(17) and disposed on other side of said clutch shaft (17);
characterized in that, said clutch assembly (15) further includes a stopper unit (18) adapted to be circumferentially disposed around said clutch shaft (17), said stopper unit (18) being disposed immediately before said gearbox assembly (16); and wherein, said stopper unit (18) including a stopper plate (18a), and a stopper washer (18b), said stopper washer (18b) being adapted to be engaged with said stopper plate (18a), arrests axial load being transferred through said clutch shaft (17) to said gearbox assembly (16).
2. The internal combustion engine (10) as claimed in claim 1, wherein the stopper unit (18) is adapted to be seated on a slot (17a) formed in the clutch shaft (17).
3. The internal combustion engine (10) as claimed in claim 1, wherein the stopper plate (18a) includes an inner diameter (18ad)

comprising plurality of plate crests (18aa) and a plurality of plate troughs (18ab), said plurality of plate crests (18aa), and said plurality of plate troughs (18ab) being formed alternatively with respect to one another.
4. The internal combustion engine (10) as claimed in claim 3, wherein the stopper plate (18a) further includes a plurality of pips (18ac) formed on a plate surface (18ra) thereof.
5. The internal combustion engine as claimed in claim 1 or claim 4, wherein the stopper plate (18a) is engaged to said stopper washer (18b) by means of said plurality of pips (18ac).
6. The internal combustion engine (10) as claimed in claim 1, wherein the stopper washer (18b) includes an internal diameter (18bd) comprising plurality of washer crests (18ba) and plurality of washer troughs.(18bb), said plurality of washer crests (18ba), and said plurality of washer troughs (18bb) being formed alternatively with respect to one another.
7. The internal combustion engine (10) as claimed in claim 6, wherein the stopper washer (18b) further includes a plurality of pip holes (18bc) formed on a washer surface (18rb) of said stopper washer (18b).
8. The internal combustion engine (10) as claimed in claim 4 or claim 7, wherein the plurality of pip holes (18bc) is adapted to receive said plurality of pips (18ac).

9. The internal combustion engine (10) as claimed in claim 1, wherein the stopper washer (18b) is made of a rigid material such as spring steel.
10. A vehicle including the internal combustion engine (10) as claimed in claims 1-9.