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
“VIBRATION DAMPER ASSEMBLY FOR MULTI-PLATE WET CLUTCH OF A VEHICLE”

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 a clutch assembly for a vehicle. More particularly, the invention is related to vibration damping assembly configured to dampen the torsional vibrations for multiplate wet clutch of two and three wheeled vehicles.

Background of the Invention

[002] A clutch is an important sub-system in the powertrain of a vehicle that does the work of smoothly engaging and disengaging the transmission / powertrain from the engine / power source. The engagement of the clutch between the engine and the drivetrain enables gentle and smooth driving of the vehicle. It also ensures the rapid shifting of the transmission, dampens the vibrations during power transmission, reduces rattling sounds and wear and tear of components, and serves as overload protection for the (entire) drivetrain.

[003] There are variety of prior art solutions to dampen the torsional vibrations in the clutch assembly with varying degree of success. Conventionally, the dampening of the torsional vibrations in the clutch assembly is achieved by means of a multitude of linear compression springs positioned in the primary gear attached to the clutch housing. The use of linear compression springs, because of its short length, leads to a high degree of linear stiffness, which causes a negative effect on dampening of the torsional vibrations in the active damping zone. The active damping zone is a region where the two / three wheeled vehicle is normally operating in higher transmission ratio most of the time, viz. higher gear ratio.
[004] Therefore, to address the aforementioned problem of the prior art solutions, there is a long-pending unmet need to provide an intelligent solution of dampening torsional vibrations that will reduce the issue of high linear stiffness and torsional vibrations coming from the power source in the active damping zone and provides improved NVH (noise, vibrations and harshness), better riding comfort and improves the durability of the clutch assembly in two and three wheeled vehicles.

Objects of the Present Invention

[005] The main objective of the invention is to provide a torsional vibration damper assembly for multiplate wet clutch of two and three wheeled vehicles.

[006] Another objective of the present invention is to provide a torsional vibration damper assembly for multiplate wet clutch of a vehicle wherein said damper assembly is configured to reduce the effective stiffness in the active damping zone.

[007] Still, the objective of the present invention is to eliminate the torsional vibrations coming from the power source in the active damping zone.

[008] Yet, the objective of the present invention is to provide a torsional vibration damper that provides better riding comfort and improved NVH performance.

[009] Yet, the objective of the present invention is to provide a torsional vibration damper assembly for multiplate wet clutch of a vehicle that is easy to manufacture, a cost-effective solution, and improves the durability of the clutch assembly.
Brief Description of the Drawings

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

[011] Figure 1 presents an exploded view of the vibration damper assembly for multiplate wet clutch of a vehicle in accordance with of the present invention.

[012] Figure 2 presents an isometric view in assembled condition of the vibration damper assembly for multiplate wet clutch of a vehicle as per the present invention.

[013] Figure 3 presents a sectional view of the damper assembly for multiplate wet clutch of a vehicle in accordance with the present invention.

[014] Figures 4a and 4b present an exploded view and assembled view, respectively of the first damping plate and primary gear of the vibration damper assembly for multiplate wet clutch of a vehicle in accordance with the present invention.

[015] Figures 5a and 5b present an exploded view and assembled view, respectively of the second damping plate and cover plate of the vibration damper assembly for multiplate wet clutch of a vehicle in accordance with the present invention.

[016] Figures 6a and 6b present an isometric front view and isometric rear view, respectively of the first damping plate of the vibration damper assembly for multiplate wet clutch of a vehicle in accordance with the present invention.
[017] Figures 7a and 7b present an isometric front view and isometric rear view, respectively of the second damping plate of the vibration damper assembly for multiplate wet clutch of a vehicle in accordance with the present invention.

[018] Figure 8 presents an exploded view of the first and second damping plates of the vibration damper assembly for multiplate wet clutch of a vehicle in accordance with the present invention.

[019] Figure 9 discloses view of the first and second damping plates in assembled condition during the working of the vibration damper assembly for multiplate wet clutch of a vehicle in accordance with the present invention.

[020] Figure 10 shows enlarged view of the meshing area of the first and second damping plates engaged with each other during the working of the vibration damper assembly for multiplate wet clutch of a vehicle as per the present invention.

[021] Figure 11 discloses the comparison of performance curve of the present invention with conventional solution of vibration dampers clearly highlighting the drastic reduction in effective stiffness in the active damping zone.

Detailed Description of the Present Invention

[022] 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. Referring to Fig. 1, vibration damper assembly (100) for multiplate wet clutch of a vehicle comprises of a clutch housing (10), a primary gear (20), a plurality of springs (26S), a first damping plate (30), a second damping plate (40), a cover plate (50), and a plurality of rivets (60).

[023] The clutch housing (10) is configured to have a flat base portion (14F) and a cylindrical hollow body (14B). The flat base portion (14F) of the clutch housing (10) has a central circular opening (12) to receive the output shaft (not shown). The cylindrical hollow body (14B) is provided with slots for mounting a stack of plates viz. friction plates and the pressure plates alternatively arranged therein. The flat base portion (14F) of the clutch housing (10) is configured to have a plurality of spring pockets (16), preferably six spring pockets, positioned around the central circular opening (12) and at a radially equal distance from the centre of the central opening (12). Further, said flat base portion (14F) has a plurality of rivet boss (18), preferably three bosses, projecting out from the flat base portion (14F) of the clutch housing (10) and each of the rivet bosses (18) is positioned radially around the central opening (12) and alternatively after two successive spring pockets (16). Each of the spring pockets (16) is provided with spring retainer plates (16G) at its either longitudinal ends opposite to the spring receiving face of the spring pocket (16).

[024] Referring to Figs. 1 to 4b, the primary gear (20) is configured to have a plurality of teeth (20T) along its outer peripheral surface, a front face (22F); a rear face (22B); a cylindrical hollow spindle (24) at the centre of the primary gear (20); a plurality of spring pockets (26), preferably six spring pockets, positioned radially around the hollow spindle (24); and a plurality of boss opening (28) positioned around the hollow spindle (24) but alternatively after two successive spring pockets (26). The said spring pockets (26) and boss openings (28) are provided in between circumferential region of the cylindrical hollow spindle (24) and the peripheral surface with teeth (20T) of the primary gear (20). A spring (26S), preferably the helical compression spring, is installed inside each of the spring pockets (26) of the primary gear (20). The boss openings (28) on the primary gear (20) and the rivet boss (18) on the base portion (14F) of the clutch housing (10) are concentric.

[025] The primary gear (20) is fitted with the clutch housing (10) with the help of boss openings (28) and the rivet boss (18) in such a way that the rear face (22B) of the primary gear (20) is rigidly interfaced with the flat base portion (14F) of the clutch housing (10) by inserting the rivet boss (18) of the clutch housing (10) in the respective boss opening (28) of the primary gear (20). The teeth (20T) of the primary gear (20) are in mesh with the gear mounted on the output shaft of the engine for transmitting torque/power to the clutch assembly. The cylindrical hollow spindle (24) is projecting out from the front face (22F) of the primary gear (20). Three guide pins (29) are provided radially at an equal angular distance on the front face (22F) around the cylindrical hollow spindle (24) of the primary gear (20).

[026] The first damping plate (30) is configured to have a front face (30F), a rear face (30B) and a central opening (30C). Further, said first damping plate (30) is provided with at least three rectangular slits (32) on its the inner peripheral surface and at least three semi-circular grooves (34) on the outer peripheral surface of the damping plate (30). The said rectangular slits (32) and said semi-circular grooves (34) of the first damping plate (30) are positioned at an equal angular distance from the centre of the first damping plate (30) but exactly facing opposite to each other. The width of the rectangular slits (32) on the first damping plate (30) is greater than the diameter of the guide pin (29) on the front face (22F) of the primary gear (20) so as to maintain the sufficient free play between the first damping plate (30) and the primary gear (20) during working of the vibration damper assembly (100).

[027] Further, the front face (30F) of the first damping plate (30) is configured to have at least three helical ridges (38E) along the circumferential direction of the first damping plate (30) and each of the helical ridge is separated by a valley (38D). Further, each of the helical ridge (38E) makes a helix angle ß and is diverging in the radial direction of said damping plate (30) and positioned at an equal angular distance from each other. The angle ß made by the helical ridge (38E) with the valley (38D) on the front face (30F) of the first damping plate (30) ranges from 30O to 70O. Each of the valley (38D) is configured to have two friction petals (30P) pasted on its rear side (36E) on the rear face (30B) of the first damping plate (30) and said friction petals (30P) are positioned on either sides of the rectangular slot (32) and the semi-circular groove (34).

[028] The first damping plate (30) is anchored with the primary gear (20) and during this anchoring the cylindrical hollow spindle (24) on the front face (22F) of the primary gear (20) passes through the central opening (30C) of the first damping plate (30) and the guide pins (29) provided on the front face (22F) of the primary gear (20) get positioned into the respective rectangular slit (32) of the first damping plate (30). Thus, the first damping plate (30) is anchored to the primary gear (20) in such a way that the friction petals (30P) pasted on the rear face (30B) of the first damping plate (30) is in contact with the front face (22F) of the primary gear (20).

[029] The second damping plate (40) is configured to have a front face (40F), a rear face (40B) and a central opening (40C). Further, said second damping plate (40) is provided with at least three rectangular slits (44) on its the outer peripheral surface and at least three semi-circular grooves (42) on the inner peripheral surface of the second damping plate (40). The said rectangular slits (44) and said semi-circular grooves (42) of the second damping plate (40) are positioned in a valley (48V) at an equal angular distance from the centre of the second damping plate (40) but exactly facing opposite to each other. The width of the rectangular slits (44) on the second damping plate (40) is greater than the diameter of the guide pin (59) on the inner face (50B) of a cover plate (50) so as to maintain the sufficient free play between the second damping plate (40) and the cover plate (50) during working of the vibration damper assembly (100).

[030] Further, the front face (40F) of the second damping plate (40) is configured to have at least six helical ridges (48E) along the circumferential direction of the second damping plate (40) and each of the helical ridge (48E) is alternatively separated by a valley (48D) and a valley (48V). Further, each of the helical ridge (48E) makes a helix angle a and is diverging in the radial direction of said damping plate (40). The angle a made by the helical ridge (48E) with the valley (48D, 48V) on the front face (40F) of the second damping plate (40) ranges from 30O to 70O. Each of the valleys (48D) is configured to have a friction petal (40P) pasted on its rear side (46E) on the rear face (40B) of the second damping plate (40). The valley (48V) is larger than that of the valley (48D). Each of the valleys (48V) is configured to have at least two friction petals (40P) pasted on its rear side (48R) on the rear face (40B) of the second damping plate (40) and said friction petals (40P) are positioned on either sides of the rectangular slot (44) and the semi-circular groove (42) provided on the outer and inner peripheral surfaces, respectively of the second damping plate (40).

[031] The second damping plate (40) is mounted over the first damping plate (30) in such a way that the front face (40F) of the second damping plate (40) is positioned over the front face (30F) of the first damping plate (30) and the valleys (48D) of the second damping plate (40) houses the helical ridges (38E) of the first damping plate (30). The cylindrical hollow spindle (24) of the primary gear (20) after passing through the central opening (30C) of the first damping plate (30) passes through the central opening (40C) of the second damping plate (40) and the cylindrical grooves (42) provided on the inner peripheral surface of the second damping plate (40) securely receives the respective guide pins (29) of the primary gear (20) after passing through the rectangular slits (32) of the first damping plate (30).

[032] The cover plate (50) is configured to have an inner face (50B), an outer face (50F), a central opening (50C), at least six spring pockets (56) positioned at a radially equal distance, and at least three thorough openings (58). Each of the said openings (58) of the cover plate (50) is positioned alternatively after a set of two spring pockets (56). The said spring pockets (56) and thorough openings (58) are provided in between the inner and outer peripheral surfaces of the cover plate (50). Each of the spring pockets (56) is provided with a spring retainer (56G) at its longitudinal ends and opposite to the spring receiving face of said spring pocket (56). Further, the inner face (50B) of the cover plate (50) is configured to have three guide pins (59) positioned at an equal angular distance and in between the inner peripheral surface of the cover plate (50) and a series of spring pockets (56).

[033] The cover plate (50) is stacked over the rear face (40B) of the second damping plate (40) in such a way that the central opening (50C) of the cover plate (50) is sleeved over the cylindrical hollow spindle (24) of the primary gear (20) thereby sandwiching the both the damping plates, the first damping plate (30) and the second damping plate (40), in between the said cover plate (50) and the primary gear (20). The guide pins (59) provided on the inner face (50B) of the cover plate (50) passes through the respective rectangular slits (44) provided on the outer peripheral surface of the second damping plate (40) and gets secured in the semi-circular grooves (34) provided on the outer peripheral surface of the first damping plate (30). This novel and inventive construction of the vibration damper assembly for the multi-plate wet clutch makes the helical ridges of the first damping plate to move over matching valleys on the second damping plate and thereby pushes each other against the cover plate and the primary gear respectively, thereby increasing the magnitude of the frictional force acting between said primary gear and the cover plate. This frictional interaction between the first damping plate and the second damping plate aids in dampening the oscillations in torque that is received by the primary gear from the engine.

[034] The thorough openings (58) of the cover plate (50) and the openings provided on the rivet boss (18) of the clutch housing (10) are concentric and of same diameter. Said thorough openings (58) are configured to face on the respective top face of the rivet boss (18) of the clutch housing (10) in such a way that both the openings are aligned concentrically to receive the rivets (60). The spring pocket (56) on the cover plate (50), the spring pocket (26) on the primary gear (20) and the spring pocket (16) on the clutch housing (10) are collectively configured to house the helical compression spring (26S) and the spring retainer (56G) provided on the cover plate (50) and the spring retainers (16G) provided on the clutch housing (10) collectively facilitate to maintain the position and orientation of the helical compression springs (26S) inside the spring pockets (16, 26, 56). The cover plate (50) sandwiching both the damping plates (30, 40) with the primary gear (20) is rigidly fitted with the clutch housing (10) by the rivets (60) by inserting the rivets (60) from outer face (50F) of the cover plate (50) and through the thorough openings (58) and the openings provided on the top face of the rives boss (18).

[035] As far as working of the vibration damper assembly is concerned, when the user drives the vehicle, the torque or power of the engine is transmitted to the primary gear (20) of the clutch housing from the gear mounted on the output shaft of the engine. The received torque or power is further transferred to the clutch housing (10). During the transfer of torque or power from the primary gear (20) to the clutch housing (10), there is a relative motion between the primary gear (20) and clutch housing (10) due to the static inertia of the clutch housing (10) and the vehicle gear box. The relative motion between the said primary gear (20) and clutch housing (10) is compensated by the helical springs (26S) by absorbing the torsional vibrations from the engine to some extent. As the vehicle is run in higher transmission ratio / higher gear and enters the active damping zone, the second damping plate (40) rotates in consensus with the primary gear (20) by virtue of the locking of the guide pins (29) within the cylindrical grooves (42) of the second damping plate (40). The rotation of the second damping plate (40) causes the rubbing of the second damping plate (40) with the first damping plate (30) until the rectangular slits (32) of the first damping plate (30) come into contact with the guide pins (29) of the primary gear (20). At this stage, the helical ridges (38E) of the first damping plate (30) and the helical ridge (48E) of the second damping plate (40) mate with each other, thus causing the first and second damping plates (30, 40) to rotate in unison. The mating of the helical ridges (38E, 48E) of the first and second damping plates (30, 40) eliminates the abrupt impact or jerk due to the sliding action achieved with the slope of the helix angle provided on the helical ridges. The relative motion between the first damping plate (30) and the second damping plate (40) is realized by virtue of the angular rotation of the rectangular slits (32) of the first damping plate (30) in the guide pins (29) of the primary gear (20) and the rectangular slits (44) of the second damping plate (40) in the guide pins (59) of the cover plate (50). Thus, the relative motion between the first damping plate (30) and the second damping plate (40) efficiently leads to absorb the torsional vibration coming from the engine in the active damping zone and thereby eliminating the rattling noise, wear and tear of the components and enhances the NVH performance of the multi-plate wet clutch as shown Fig. 11. The friction petals (30P) provided on the rear face (30B) of the first damping plate (30) and the friction petals (40P) provided on the rear face (40B) of the second damping plate (40) facilitate to provide an uninterrupted transmission of power between the primary gear (20) and the clutch housing (10).

[036] The vibration damper assembly of the present invention, in accordance with the discussed embodiment, provides the following technical advantages that contribute to the technical advancement of the vibration damper for multi-plate wet clutch of a vehicle:
- The vibration damper assembly of the present invention drastically reduces the effective stiffness in the active damping zone upto 60 per cent and thereby eliminates the torsional vibrations coming from the power source in the active damping zone.
- The vibration damper assembly of the present invention improves the durability of the multi-plate wet clutch of a vehicle.
- The present invention provides improved NVH performance and thereby imparts better riding comfort to the user.
- The present invention provides a very simple, easy to manufacture and assembly, easy to maintain and a cost-effective solution for dampening the torsional vibrations.

[037] The foregoing description of the specific embodiment of the invention will so fully reveal the general nature of the embodiment herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiment without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiment. 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 embodiment herein has been described in terms of preferred embodiment, those skilled in the art will recognize that the embodiment herein can be practiced with modification within the spirit and scope of the embodiment as described herein. , Claims:We Claim

1. A vibration damper assembly (100) for multiplate wet clutch of a vehicle comprising of a clutch housing (10), a primary gear (20), a first damping plate (30), a second damping plate (40), a plurality of springs (26S), a cover plate (50), and a plurality of rivets (60); wherein
- the clutch housing (10) is configured to have a flat base portion (14F) and a cylindrical hollow body (14B); said flat base portion (14F) of the clutch housing (10) is configured to have six spring pockets (16) positioned around a central circular opening (12) and three rivet bosses (18) projecting out from the flat base portion (14F) of the clutch housing (10); and each of the rivet bosses (18) is positioned radially around the central opening (12) and alternatively after two successive spring pockets (16);
- the primary gear (20) is configured to have a cylindrical hollow spindle (24) projecting out from the centre of a front face (22F) of the primary gear (20), at least three guide pins (29) positioned radially at an equal angular distance around said cylindrical hollow spindle (24) on the front face (22F) of the primary gear (20), and a plurality of teeth (20T) along its outer peripheral surface;
- the first damping plate (30) is configured to have at least three helical ridges (38E) on its front face (30F) along the circumferential direction and each of said helical ridges (38E) is separated by a valley (38D), at least three rectangular slits (32) on its the inner peripheral surface, and at least three semi-circular grooves (34) on the outer peripheral surface of said damping plate (30);
- the second damping plate (40) is configured to have at least six helical ridges (48E) on its front face (40F) along the circumferential direction and each of the helical ridge (48E) is separated alternatively by a valley (48D) and a valley (48V), at least three rectangular slits (44) on its outer peripheral surface, and at least three semi-circular grooves (42) on the inner peripheral surface of said second damping plate (40);
- the cover plate (50) is configured to have at least three guide pins (59) positioned on its inner face (50B) at an equal angular distance and in between the inner peripheral surface of the cover plate (50) and a series of spring pockets (56), at least six spring pockets (56) positioned at a radially equal distance, and at least three thorough openings (58); and
- said cover plate (50) is stacked over a rear face (40B) of the second damping plate (40) in such a way that the central opening (50C) of the cover plate (50) is sleeved over the cylindrical hollow spindle (24) of the primary gear (20) thereby sandwiching the first damping plate (30) and the second damping plate (40) in between the cover plate (50) and the primary gear (20).

2. The vibration damper assembly (100) for multiplate wet clutch as claimed in claim 1, wherein
- the rectangular slits (32) and said semi-circular grooves (34) of the first damping plate (30) are positioned at an equal angular distance from the centre of the first damping plate (30) but exactly facing opposite to each other; and
- the width of the rectangular slits (32) on the first damping plate (30) is greater than the diameter of the guide pin (29) on the front face (22F) of the primary gear (20) so as to maintain the sufficient free play between the first damping plate (30) and the primary gear (20).

3. The vibration damper assembly (100) for multiplate wet clutch as claimed in claim 2, wherein
- each of the helical ridges (38E) is configured to have diverging profile in the radial direction of said damping plate (30) making a helix angle ß and positioned at an equal angular distance from each other; and
- each of the valley (38D) is configured to have at least two friction petals (30P) pasted on its rear side (36E) on the rear face (30B) of the first damping plate (30) and said friction petals (30P) are positioned on either sides of the rectangular slot (32) and the semi-circular groove (34).

4. The vibration damper assembly (100) for multiplate wet clutch as claimed in claim 3, wherein the angle ß made by the helical ridge (38E) with the valley (38D) on the front face (30F) of the first damping plate (30) ranges from 30O to 70O.

5. The vibration damper assembly (100) for multiplate wet clutch as claimed in claim 4, wherein
- the first damping plate (30) is anchored with the primary gear (20) in such a way that the cylindrical hollow spindle (24) on the front face (22F) of the primary gear (20) passes through the central opening (30C) of the first damping plate (30) and the guide pins (29) on the front face (22F) of the primary gear (20) get positioned into the respective rectangular slits (32) of the first damping plate (30); and
- the friction petals (30P) pasted on the rear face (30B) of the first damping plate (30) is in contact with the front face (22F) of the primary gear (20).

6. The vibration damper assembly (100) for multiplate wet clutch as claimed in claim 1, wherein
- the rectangular slits (44) and said semi-circular grooves (42) of the second damping plate (40) are positioned in a valley (48V) at an equal angular distance from the centre of the second damping plate (40) but exactly facing opposite to each other; and
- the width of the rectangular slits (44) on said second damping plate (40) is greater than the diameter of the guide pin (59) on the inner face (50B) of a cover plate (50) so as to maintain the sufficient free play between the second damping plate (40) and the cover plate (50) of the vibration damper assembly (100).

7. The vibration damper assembly (100) for multiplate wet clutch as claimed in claim 6, wherein
- each of the helical ridges (48E) is configured to have diverging profile in the radial direction of said damping plate (40) and makes a helix angle a on its either side with the valley (48D, 48V);
- each of the valleys (48D) is configured to have a friction petal (40P) pasted on its rear side (46E) on the rear face (40B) of the second damping plate (40);
- each of the valleys (48V) is configured to have at least two friction petals (40P) pasted on its rear side (48R) on the rear face (40B) of the second damping plate (40); and
- said friction petals (40P) are positioned on either sides of the rectangular slot (44) and the semi-circular groove (42) positioned on the outer and inner peripheral surfaces, respectively of said second damping plate (40).

8. The vibration damper assembly (100) for multiplate wet clutch as claimed in claim 7, wherein the angle a made by the helical ridge (48E) with the valley (48D, 48V) on the front face (40F) of the second damping plate (40) ranges from 30O to 70O.

9. The vibration damper assembly (100) for multiplate wet clutch as claimed in claim 8, wherein
- the second damping plate (40) is mounted over the first damping plate (30) in such a way that the front face (40F) of the second damping plate (40) is positioned over the front face (30F) of the first damping plate (30) and the valleys (48D) of the second damping plate (40) houses the helical ridges (38E) of the first damping plate (30); and
- the cylindrical grooves (42) provided on the inner peripheral surface of the second damping plate (40) securely receives the respective guide pins (29) of the primary gear (20) after passing through the rectangular slits (32) of the first damping plate (30).

10. The vibration damper assembly (100) for multiplate wet clutch as claimed in claim 6, wherein the guide pins (59) provided on the inner face (50B) of the cover plate (50) passes through the respective rectangular slits (44) provided on the outer peripheral surface of the second damping plate (40) and gets secured in the semi-circular grooves (34) provided on the outer peripheral surface of the first damping plate (30).

11. The vibration damper assembly (100) for multiplate wet clutch as claimed in claim 10, wherein
- each of the thorough openings (58) of the cover plate (50) is positioned alternatively after a set of two spring pockets (56);
- said spring pockets (56) and thorough openings (58) are positioned in between the inner and outer peripheral surfaces of the cover plate (50);
- the thorough openings (58) of the cover plate (50) and the openings provided on the rivet boss (18) of the clutch housing (10) are of same diameter and said thorough openings (58) are configured to face on the respective top face of the rivet boss (18) of the clutch housing (10) in such a way that both the openings are aligned concentrically to receive the rivets (60); and
- each of the spring pockets (56) is provided with a spring retainer (56G) at its longitudinal ends and opposite to the spring receiving face of said spring pocket (56).

12. The vibration damper assembly (100) for multiplate wet clutch as claimed in claim 11, wherein the cover plate (50) sandwiching both the damping plates (30, 40) with the primary gear (20) is rigidly fitted with the clutch housing (10) by inserting the rivets (60) through the thorough openings (58) on the outer face (50F) of the cover plate (50) and the openings provided on the top face of the rives boss (18).

13. The vibration damper assembly (100) for multiplate wet clutch as claimed in claim 12, wherein
- the primary gear (20) is configured to have six spring pockets (26) and three boss openings (28) positioned radially around the hollow spindle (24) and each of the said boss openings (28) is located alternatively after two successive spring pockets (26);
- the said spring pockets (26) and boss openings (28) are positioned in the circumferential region between the cylindrical hollow spindle (24) and the peripheral surface with teeth (20T) of the primary gear (20); and
- said boss openings (28) on the primary gear (20) and the rivet boss (18) on the base portion (14F) of the clutch housing (10) are concentric.

14. The vibration damper assembly (100) for multiplate wet clutch as claimed in claim 13, wherein the primary gear (20) is fitted with the clutch housing (10) with the help of boss openings (28) and the rivet boss (18) in such a way that the rear face (22B) of the primary gear (20) is interfaced with the flat base portion (14F) of the clutch housing (10) by getting the rivet boss (18) of the clutch housing (10) inserted into the respective boss opening (28) of the primary gear (20).

15. The vibration damper assembly (100) for multiplate wet clutch as claimed in claim 14, wherein
- the flat base portion (14F) of the clutch housing (10) is configured to have six spring pockets (16) positioned around a central circular opening (12) and at a radially equal distance from the centre of the central opening (12) of the clutch housing (10); and
- each of the spring pockets (16) is provided with spring retainer plates (16G) at its either longitudinal ends opposite to the spring receiving face of the spring pocket (16) of said clutch housing (10).

16. The vibration damper assembly (100) for multiplate wet clutch as claimed in any of the claims 5, 9 and 14, wherein
- the spring pockets (56) on the cover plate (50), the spring pockets (26) on the primary gear (20) and the spring pockets (16) on the clutch housing (10) are configured to collectively house the springs (26S);
- the spring retainer (56G) provided on the cover plate (50) and the spring retainers (16G) provided on the clutch housing (10) are configured to collectively maintain the position and orientation of the springs (26S) inside the spring pockets (16, 26, 56); and
- the spring (26S) is selected from the helical compression spring.

Dated this 1st day of Sept. 2023

Sahastrarashmi Pund
Head – IPR
Endurance Technologies Ltd.

To,
The Controller of Patents,
The Patent Office, at Mumbai.