Claims:We Claim

1. A clutch (100) having a damping sub-assembly (101) for two wheeled and three wheeled vehicles, said damping sub-assembly comprises of a clutch housing (10), a plate (20), an inner boss (30), a plurality of helical springs (40) and a plurality of fastening structures (50),
wherein,
- the clutch housing (10) has a cylindrical structure with a closed side (10CS) and an open side, said closed side (10CS) has an opening (11) in the center and a circular projection (15) originates at the base of the opening (11) and terminates within the cylindrical structure of the clutch housing (10); a plurality of circular recesses on an inner surface of a closed side (10CS) of the clutch housing (10) around the opening (11) forming the spring seats (12) and each of the spring seats (12) has a circular opening (12O); and a plurality of slots (13) on its inside curved surface, said slots (13) originate at the open side and proceed linearly towards the closed side (10CS) and terminate within the clutch housing (10) before reaching the closed side (10CS) of the clutch housing (10);
- the plate (20) has a circular profile with ridges (21) on its radially outward surface, the profile of said ridges (21) match with the profile of slots (13) thereby allowing the ridges (21) and thereby the plate (20) to slide within the slots (13) of the housing (10); and a plurality of circular recesses on its inner flat surface forming the spring seats (23) and each of the spring seats (23) is at equal distance from the center of the plate (20); and
- the plate (20) through its ridges (21) is locked inside the slots (13) of the clutch housing (10) in such a way that the spring seats (12) on the inner surface of the closed side (10CS) of the housing (10) are offset in horizontal plane by an angle (a) with the respective spring seats (23) on the inner surface of the plate (20).

2. The clutch (100) for two wheeled and three wheeled vehicles as claimed in claim 1, wherein a pair of the spring seat (12) on the clutch housing and the respective spring seat (23) on the plate (20) holds the helical spring (40) in such way that said helical spring is skewed by an angle (ß) with the vertical.

3. The clutch (100) for two wheeled and three wheeled vehicles as claimed in claim 2, wherein
- the circular opening (12O) given on the closed side (10CS) of the housing (10) is coaxial with the axis of the spring seat (12);
- the spring seats (12) are at equal distance from the center of the opening (11) and each of the spring seats (12) on the housing (10) accommodating one end of the helical springs (40) is spaced from the successive spring seat by an angular distance (?) made with the center of the opening (11) by the spring seats (12);
- the slot (13a) of the housing (10), after every two successive slots (13), has an open end (14) originating at the open side of the housing (10) and terminates along an imaginary plane parallel to the closed side (10CS) of the housing (10);
- each of the spring seats (23) on the plate (20) accommodating other end of the helical springs (40) is spaced from the successive spring seat by an angular distance (?’) made with the center of the plate (20) by the spring seats (23); and
- the plate (20) has a circular groove (26) on its outer flat surface (20A) which distinguishes a radially inward flat surface (20B) of the plate (20) from the radially outward flat surface (20C) of the plate (20) and the radially inward flat surface (20B) of the plate (20) has a series of evenly distributed outer holes (24) and another series of evenly distributed inner holes (25).

4. The clutch (100) for two wheeled and three wheeled vehicles as claimed in claim 3, wherein the angular distance (?) between the successive spring seats (12) on the clutch housing (10) is equal to the angular distance (?’) between the successive spring seats (23) on the plate (20) depending on the number of helical springs (40).

5. The clutch (100) for two wheeled and three wheeled vehicles as claimed in claim 4, wherein the offset angle (a) is in the range of 3 to 5 degrees.

6. The clutch (100) for two wheeled and three wheeled vehicles as claimed in claim 5, wherein the angle (ß) made by the helical spring (40) hold between the spring seat (12) on the housing (10) and the spring seat (23) on the plate (20) with the vertical is in the range of 3 to 5 degree.

7. The clutch (100) for two wheeled and three wheeled vehicles as claimed in claim 6, wherein
- the inner boss (30) has a hollow cylindrical shape with at least one smaller outer diameter section (31), at least one larger outer diameter section (32), and at least one annular ring section (33) on outer surface of the larger outer diameter section (32); the annular ring section (33) has a set of holes (34) matching the position of the holes (24) as provided within the plate (20); and the fastening means (50) passing through holes (34) and holes (24) fasten the inner boss (30) to the plate (20); and
- a portion (32A) of the larger outer diameter section (32) surrounds the circular projection (15) of the clutch housing (10) and allows a sliding bush to be positioned between the outer surface of the circular projection (15) and the inner surface of the sub portion (32A); and the smaller outer diameter section (31) has vertical slots (31S) on its inner curved surface that begin at one open end of the smaller outer diameter section (31) and terminate along a section where the smaller diameter section (31) merges with the larger outer diameter section (32).

8. The clutch (100) for two wheeled and three wheeled vehicles as claimed in claim 7, wherein
- a plurality of clutch plates (70) are mounted in the slots (62) provided on the clutch hub (60) in a manner such that the conical disc spring (51) is located between the last of the plurality of clutch plates (70) and the plate (20);
- a plurality of friction plates (80) are mounted in slots (13) given on the clutch housing (10) such that they are located alternatively with the clutch plates (70) mounted on the clutch hub (20) thereby forming a stack of plurality clutch and friction plates (70 and 80); and
- a cover plate (90) is mounted on the open side of the clutch housing (10) in a manner such that it encloses the components located within the clutch housing (10).

9. The clutch (100) for two wheeled and three wheeled vehicles as claimed in claim 8, wherein
- the circular groove (26) on the plate (20) accommodates a conical disc spring (51);
- a clutch hub (60) having a hollow cylindrical shape with a larger diameter section (60L) and a lower diameter section (60S) and an inner profile matching the external profile of the inner boss (30) is positioned over the inner boss (30); and the larger diameter section (60L) is provided with slots (62) on its outer curved surface that proceed linearly from one end of the large diameter section (60L) to the other end of the large diameter section;
- a set of sliding bushes (61) are positioned between the inner surface of the lower diameter section (60S) and the outer surface of the low outer diameter section (31); and
- a portion (35) of the clutch hub (60) projects outwards from a central opening (91) of the cover plate (90) and said portion (35) of the clutch hub (60) has a gear (36) on its outer curved surface.

10. The clutch (100) for two wheeled and three wheeled vehicles as claimed in claim 9, wherein
- the portion (35) of the clutch hub (60) is provided with through openings (35O) that are located between the gear (36) and the cover plate (90),
- a set of evenly distributed slots (30S) on the outer flat surface (37) of the larger diameter section (32) formed along the plane in which the larger outer diameter section (32) merges with the lower diameter section (31);
- the large diameter section (60L) of the clutch hub (60) is provided with through openings (60H);
- the clutch housing (10) has through openings (10H) on its cylindrical surface;
- the through openings (35O), the clearance given between the inner boss (30) and the clutch hub (60), the evenly distributed slots (30S), the through openings (60H), the through openings (10H) and openings (14) together constitute an oil flow path permitting flow of a lubrication fluid; and
- the openings (12O), the plurality of helical springs (60), a set of evenly distributed through openings (25) given along the inner diameter of the plate (20), the clearance given between the inner boss (30) and the clutch hub (60), the through openings (60H), the through openings (10H) and the openings (14) together constitute another oil flow path permitting flow of a lubrication fluid.

Dated this 7th day of March 2022

Sahastrarashmi Pund
Head – IPR
Endurance Technologies Ltd.

To,
The Controller of Patents,
The Patent Office, at Mumbai. , Description:FORM 2
The Patent Act 1970
(39 of 1970)
&
The Patent Rules, 2005

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

TITLE OF THE INVENTION
“CLUTCH FOR TWO AND THREE WHEELED VEHICLES”

Endurance Technologies Limited
E-92, M.I.D.C. Industrial Area, Waluj,
Aurangabad – 431136, Maharashtra, India

The following specification particularly describes and ascertains the nature of this invention and the manner in which it is to be performed.

Field of Invention

[001] The present invention is related to clutches provided in two and three wheeled motor vehicles. It more particularly relates to the uniquely designed damping assembly of the clutch that reduces noise and vibrations and provide a simple, compact and robust structure.

Background of the Invention

[002] Conventional clutch assemblies are provided with damping springs that are primarily accommodated in openings given in a gear wheel and confined and held in their position by structures provided on a plate and a clutch housing. The plate and the clutch housing so provided are in turn connected to each other by fastening means such as rivets. These damping springs function to dampen oscillations in torque input being received by the gear wheel from an engine gear. Vibrations resulting from other causes such lack of gradual engagement or disengagement between clutch and friction plates are dealt by providing additional strategically positioned springs and/or other equivalent damping means within the clutch assembly. As adding bulk/mass typically tends to aid in managing the intensity of noise and vibration, any such addition is normally considered doubly advantageous.

[003] The conventional solutions for managing NVH (Noise, Vibration and Harshness) therefore normally end up adding bulk/weight to the clutch assembly. While reducing weight and resolving NVH issue is important, any trade-off that reduces the reliability and robustness of the clutch assembly also have to be avoided. As such, there is an existing need for a simple, light weight and durable clutch assembly that works efficiently and has better NVH characteristics than that of existing clutch assemblies.

Objectives of the Present Invention

[004] The main object of the present invention is to provide an efficient clutch for utilization in a two and three wheeled motor vehicle.

[005] Another objective of the present invention is to provide a clutch that deals with issues of noise and vibration effectively.

[006] Yet another objective of the present invention is to provide a clutch that has light weight and durable construction.

[007] Still another objective of the present invention is to provide a clutch that is reliable and robust.

[008] Further objective of the present invention is to provide a clutch that has a simple construction and is therefore easy to manufacture.

Brief Description of Drawings

[009] This invention is illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein and advantages thereof will be better understood from the following description when read in conjunction with the following drawings, wherein

[0010] Figure 1 discloses cross sectional view of a clutch for two and three wheeled vehicle in accordance with the present invention.

[0011] Figure 2a and Figure 2b discloses perspective of the clutch from an angle and the other angle, respectively in accordance with the present invention.

[0012] Figure 3 presents the top view of the clutch disclosing offset of the spring seats in accordance with the present invention.

[0013] Figure 4a shows the cross sectional view of the clutch disclosed in Fig 4b in accordance with the present invention

[0014] Figure 4b shows the perspective cut-view of the clutch of the invention

Detailed Description of the Present Invention

[0015] The invention will now be described in detail with reference to the accompanying drawings which must not be viewed as restricting the scope and ambit of the invention.

[0016] In accordance with the disclosed preferred embodiment of the invention a clutch (100) having a damping sub-assembly (101) for two wheeled and three wheeled vehicles, with said damping sub-assembly comprising of a clutch housing (10), a plate (20), an inner boss (30), a plurality of helical springs (40) and a plurality of fastening structures (50).

[0017] Referring to Figs. 1, 2a and 2b the clutch housing (10) of the clutch has a cylindrical structure with a closed side (10CS) and an open side (10OS). The closed side (10CS) has an opening (11) in the center and a circular projection (15) that originates at the base of the opening (11) and terminates within the cylindrical structure of the clutch housing (10). The opening (11) and the circular projection (15) provide the required confined space for accommodating and supporting a clutch actuation means (not shown). The clutch actuation means (not shown) is typically linked with a clutch lever that is mounted either on the handlebar or along with other foot pedals of the motor vehicle user. A plurality of circular recesses are provided on an inner surface of a closed side (10CS) of the clutch housing (10) around the opening (11) forming the spring seats (12). Each of the spring seats (12) have a circular opening (12O) that allows lubricating oil splashing around in the transmission to enter the clutch housing (10). This opening therefore aids in cooling as well as lubrication of the clutch components during vehicle operation. The circular opening (12O) given on the closed side (10CS) of the housing (10) are coaxial with the axis of the spring seats (12).

[0018] A plurality of slots (13) are given on the inside curved surface of the clutch housing (10). The slots (13) originate at the open side and proceed linearly towards the closed side (10CS) and terminate within the clutch housing (10) before reaching the closed side (10CS) of the clutch housing (10). The plate (20) of the damping sub-assembly (100) (refer Figs. 2a and 2b), has a circular profile with ridges (21) on its radially outward surface, the profile of said ridges (21) match with the profile of slots (13) thereby allowing the ridges (21) and thereby the plate (20) to slide within the slots (13) of the housing (10). A plurality of circular recesses on the plate (20) inner flat surface form the spring seats (23). Each of the spring seats (23) is at equal distance from the center of the plate (20).

[0019] The plate (20) through its ridges (21) is locked inside the slots (13) of the clutch housing (10) in such a way that the spring seats (12) on the inner surface of the closed side (10CS) of the housing (10) are offset in horizontal plane by an angle (a) with the respective spring seats (23) on the inner surface of the plate (20). The offset angle (a) is in the range of 3 to 5 degrees. A pair of the spring seat (12) on the clutch housing (10) and the respective spring seat (23) on the plate (20) holds the helical spring (40) in such way that said helical spring is skewed by an angle (ß) with the vertical. The angle (ß) made by the helical spring (40) held between the spring seat (12) on the housing (10) and the spring seat (23) on the plate (20) with the vertical is in the range of 3 to 5 degree. The angles (a and ß) are significant because they enable effective reduction of noise and vibration within the clutch (100) utilizing only helical springs (40) for this purpose. Maintaining these angles (a and ß) can even permit reduction or removal of other means of noise and vibration reduction as may be provided in a clutch assembly thereby aiding in weight reduction. The spring seats (12) are at equal distance from the center of the opening (11) and each of the spring seats (12) on the housing (10) accommodating one end of the helical springs (40) is spaced from the successive spring seat by an angular distance (?) made with the center of the opening (11) by the spring seats (12).

[0020] The slot (13a) of the housing (10), after every two successive slots (13), has an open end (14) originating at the open side of the housing (10) and terminates along an imaginary plane parallel to the closed side (10CS) of the housing (10). Each of the spring seats (23) on the plate (20) accommodating other end of the helical springs (40) is spaced from the successive spring seat by an angular distance (?’) made with the center of the plate (20) by the spring seats (23). The plate (20) has a circular groove (26) on its outer flat surface (20A) which distinguishes a radially inward flat surface (20B) of the plate (20) from the radially outward flat surface (20C) of the plate (20) and the radially inward flat surface (20B) of the plate (20) has a series of evenly distributed outer holes (24) and another series of evenly distributed inner holes (25). The angular distance (?) between the successive spring seats (12) on the clutch housing (10) is equal to the angular distance (?’) between the successive spring seats (23) on the plate (20) depending on the number of helical springs (40). Maintaining equal angles (? and ?’) ensures that the offset angle of spring seats (a) and the tilt angle of the spring (ß) given in the range as specified does not end up negatively affecting the compressive force/clamping load that is required to be provided by the helical springs (40) for ensuring proper clutch operation (i.e. proper clutch engagement/disengagement).

[0021] The inner boss (30) has a hollow cylindrical shape with at least one smaller outer diameter section (31), at least one larger outer diameter section (32), and at least one annular ring section (33) on outer surface of the larger outer diameter section (32). The annular ring section (33) has a set of holes (34) matching the postion of the holes (24) as provided within the plate (20). The fastening means (50) passing through holes (34) and holes (24) fasten the inner boss (30) to the plate (20). A portion (32A) of the larger outer diameter section (32) surrounds the circular projection (15) of the clutch housing (10) and allows a sliding bush to be positioned between the outer surface of the circular projection (15) and the inner surface of the sub portion (32A). The smaller outer diameter section (31) has vertical slots (31S) on its inner curved surface that begin at one open end of the smaller outer diameter section (31) and terminate along a section where the smaller diameter section (31) merges with the larger outer diameter section (32).

[0022] A plurality of clutch plates (70) are mounted in the slots (62) provided on the clutch hub (60) in a manner such that a conical disc spring (51) is located between the last of the plurality of clutch plates (70) and the plate (20). The circular groove (26) given on the plate (20) accommodates this conical disc spring (51). A plurality of friction plates (80) are mounted in slots (13) given on the clutch housing (10) such that they are located alternatively with the clutch plates (70) mounted on the clutch hub (20) thereby forming a stack of plurality clutch and friction plates (70 and 80). A cover plate (90) is mounted on the open side of the clutch housing (10) in a manner such that it encloses the components located within the clutch housing (10).

[0023] A clutch hub (60) having a hollow cylindrical shape with a larger diameter section (60L) and a lower diameter section (60S) and an inner profile of the clutch hub (60) matching the external profile of the inner boss (30) is positioned over the inner boss (30). The larger diameter section (60L) is provided with slots (62) on its outer curved surface that proceed linearly from one end of the large diameter section (60L) to the other end of the large diameter section. A set of sliding bushes (61) are positioned between the inner surface of the lower diameter section (60S) and the outer surface of the low outer diameter section (31). A portion (35) of the clutch hub (60) projects outwards from a central opening (91) of the cover plate (90) and said portion (35) of the clutch hub (60) has a gear (36) on its outer curved surface.

[0024] The portion (35) of the clutch hub (60) is provided with through openings (35O) that are located between the gear (36) and the cover plate (90). A set of evenly distributed slots (30S) on the outer flat surface (37) of the larger diameter section (32) formed along the plane in which the larger outer diameter section (32) merges with the lower diameter section (31). The large diameter section (60L) of the clutch hub (60) is provided with through openings (60H). The clutch housing (10) has through openings (10H) on its cylindrical surface. The through openings (35O), the clearance given between the inner boss (30) and the clutch hub (60), the evenly distributed slots (30S), the through openings (60H), the through openings (10H) and openings (14) together constitute an oil flow path permitting flow of a lubrication fluid within the clutch (100). The openings (12O), the plurality of helical springs (40), a set of evenly distributed through openings (25) given along the inner diameter of the plate (20), the clearance given between the inner boss (30) and the clutch hub (60), the through openings (60H), the through openings (10H) and the openings (14) together constitute another oil flow path permitting flow of a lubrication fluid within the clutch (100).

[0025] When the clutch lever (not shown in the figure) is operated, a clutch actuation means causes the plate (20) to be moved further into the clutch housing (10). The movement of the plate (20) allows the plurality of clutch and friction plates (70 and 80) to move apart and separate thereby allowing the clutch (100) to disengage. During clutch disengagement, when the plurality of clutch and friction plates (70 and 80) are still slipping over one another, the frictional interaction generates heat that is evacuated by the lubricating oil flowing through the oil flow path as detailed in earlier paragraphs. Once the separation of plurality of clutch and friction plate (70 and 80) is completed, torque transmission between the clutch hub (60) to the clutch housing (10) and then onto the gear box through gears stops.

[0026] As the plate (20) is being displaced within the clutch housing (10), a reaction force is setup in the plurality of helical springs (40) because of its compression. The two ends of the helical springs (40) are positioned within spring seats (12 and 23) respectively. These spring seats (12 and 23) are offset by an angle (a) from each other (refer Fig. 3). The helical spring (40) itself tilted by an angle (ß) with respect to the base of the spring seats (12 and 23). These angles allow the components of reaction force of the helical spring (40) to act so as to balance out and thereby dampen other forces which may be causing oscillations/vibrations and noise within the clutch (100). As such it may be noted here that giving helical springs (40) at the specified angles (a and ß) at the very least eliminates the need for giving any additional springs (or even conventional frictional damper plates) within the clutch (100) for reducing vibrations emerging from oscillations in the engine torque input. The clutch (100) therefore has a comparably simpler construction which makes it easier to manufacture as compared to convention clutches for two and three wheeled vehicles.

[0027] When the user stops operating the clutch lever, the actuation means returns to its original postion and the plate (20) now moving under the reaction force exerted by the helical springs (40) causes the clutch and friction plates (70 and 80) to move closer and come into firm contact with each other. Before a firm contact is established between the plurality of clutch and friction plates (70 and 80), the slippage of clutch and friction plates (70 and 80) generates heat which is again evacuated by the lubricating oil flowing through the oil flow path as detailed earlier in earlier paragraphs. Once firm contact is reestablished, normal torque transmission between the clutch hub (60) and the clutch housing (10) is resumed.

[0028] The clutch (100) in accordance with the disclosed embodiment derives the following technical advantages:
- The clutch of the invention totally eliminates the requirement of dedicated damping spring, thus reducing the number of components.
- The disclosed clutch deals effectively with issues of noise and vibration.
- The disclosed clutch that has a relatively light weight and durable construction.
- The disclosed clutch is more reliable and robust.
- The disclosed clutch has a simple construction and is therefore easy to manufacture.
- The disclosed clutch is at least as efficient as other heavier conventional clutches.

[0029] The disclosed invention hence overcomes the limitation of conventional solutions for resolving noise and vibration issues in clutches utilized in two and three wheelers. The disclosed embodiment of the clutch can be provided in relation with any suitable system for proper lubrication of the clutch while still permitting a reduction in vibration and noise associated with the clutch. Hence, any change in the lubrication system must not be seen as placing the clutch outside the scope of claims of this invention.

[0030] It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.