Claims:We Claim

1. A lubrication system for multiplate wet clutch assembly (100) of a vehicle comprising of
- a clutch housing (20) having a clutch hub (10), a plurality of friction plates (30), a plurality of clutch plates (40), a pressure plate (50), a plurality of clamping springs (60), a belleville spring (70) and a cover plate (80) encompassed therein; and
- a clutch outer case (90)
wherein,
- the clutch housing (20) has a circular rib (24) on the outer flat surface (23) projecting out at outer periphery of said outer flat surface (23) and encircling a plurality of openings (22) of the clutch housing (20) from the outside;
- the clutch outer case (90) is configured to have at least three ribs (92) and a curved projection (94) on its inner surface; said ribs (92) are spaced apart by an angular distance (a) and originate at the edge of the central hole (96) of the clutch outer case (90) and proceed radially outward and then along the inner curved surface of the clutch outer case (90); and said curved projection (94) on the inner surface of the clutch outer case (90) is positioned opposite to the ribs (92) at a location below the central hole (96) of the clutch outer case (90); and
- the clutch housing (20) mounted on an engine output shaft / gear box input shaft through the clutch hub (10) is positioned inside the clutch outer case (90) in such way that the clutch hub (10), the clutch housing (20) and the clutch outer case (90) are coaxial; and the curved projection (94) of the clutch outer case (90) makes an overlap (M’) with the circular rib (24) of the clutch housing (20) from its inner side to make a hydraulic communication with the openings (22) of the clutch housing (20) to form an optimized lubrication flow path for the clutch assembly.

2. The lubrication system for multiplate wet clutch assembly as claimed in claim 1, wherein the curved projection (94) is so positioned on the inner surface of the clutch outer case (90) that the either extreme corners of the curved projection (94) makes an angle (ß) with the center point of the origin of the center rib (92b) to hydraulically communicate with the openings (22) given on the clutch housing (20).

3. The lubrication system for multiplate wet clutch assembly as claimed in claim 2, wherein
- the angle (ß) made by the extreme corners of the curved projection (94) of the outer case (90) with the center point of the origin of the center rib (92b) is in the range of 25 to 110 degree; and
- the outer case (90) has strengthening ribs (93) of varying lengths projecting out along the outer edge of to the central hole (96) on the inner surface of the clutch outer case (90) for enhancing structural strength of the outer case (90).

4. The lubrication system for multiplate wet clutch assembly as claimed in claim 3, wherein the angular distance (a) between the successive two ribs (92) is in the range of 15 to 45 degree.

5. The lubrication system for multiplate wet clutch assembly as claimed in claim 4, wherein
- the cross sectional profile of the ribs (92) is selected from a set of profiles of rectangle and right trapezoid; and
- the height (h) of the ribs (92) is in the range of 0.05 to 0.10 times of the inner radius (Rc) of the clutch outer case (90).

6. The lubrication system for multiplate wet clutch assembly as claimed in claim 5, wherein
- the cross sectional profile of the circular rib (24) on the clutch housing (20) is selected from a set of profiles of a rectangle and right trapezoids; and
- the height (h2) of the rib (24) is in the range of 0.12 to 0.25 times of the radius (Rh) of the circular rib (24).

7. The lubrication system for multiplate wet clutch assembly as claimed in claim 6, wherein
- the cross sectional profile of the curved projection (94) on the clutch outer case (90) is right trapezoid; and
- the height (H) of the curved projection (94) is 0.4 to 0.6 times the inner radius (Rc) of the clutch outer case (90).

8. The lubrication system for multiplate wet clutch assembly as claimed in claim 7, wherein the slope (?) of the slanting side of a right trapezoid profile of the curved projection (94) and the circular rib (24) is in the range of 3 to 5 degree.

9. The lubrication system for multiplate wet clutch assembly as claimed in claim 8, wherein the overlap (M’) of the curved projection (94) of the clutch outer case (90) inside the circular rib (24) of the clutch housing (20) is in the range of 40 to 60 per cent of the height (h2) of the circular rib (24) to make hydraulic communication with the openings (22) for an effective lubrication of the clamping springs (60) and optimized recirculation of the lubrication fluid.

10. The lubrication system for multiplate wet clutch assembly as claimed in any of the claims 2 and 9, wherein
- the clutch housing (20) encompasses the clutch hub (10) in a manner such that at least one portion of the clutch housing (20) is mounted and supported coaxially upon a coaxial inner boss (14) of the clutch hub (10) via bush located between said clutch housing (20) and said coaxial inner boss (14);
- a plurality of friction plate (30) are mounted on the clutch housing (20) and a plurality of clutch plates (40) are mounted on the clutch hub (10) in a manner such that said plurality of friction plates (30) and said plurality of clutch plates (40) are positioned alternatively with each other thereby forming a stack of plurality of friction and clutch plates (30 and 40);
- a pressure plate (50) is mounted and supported coaxially upon the coaxial inner boss (14) of the clutch hub (10) in a manner such that one surface of said pressure plate (50) pushes against the last of the clutch plates (40) and locates one end of plurality of clamping springs (60) in spring seat formed on the other surface of said pressure plate (50), the belleville spring (70) is positioned within a circular groove given on one surface of the said pressure plate (50) such that said belleville spring (70) is located between the last of the plurality of clutch plates (40) and the pressure plate (50);
- the other end of plurality of clamping springs (60) is located in spring seats given on flat inside surface of the clutch housing (20), the spring seats so provided on the flat inside surface of the clutch housing (20) have openings (22) located along the central axis of plurality of clamping springs (60), a circular rib (24) projecting out the outer flat surface (23) of the clutch housing (20) encompasses the openings (22) from the outside;
- the cover plate (80) is mounted and fixed on the clutch housing (20) in manner such that said cover plate (80) closes an open end of the clutch housing (20); and
- said clutch outer case (90) surrounds the unit formed by the clutch hub (10), the clutch housing (20) and the components provided thereon in such way that the clutch outer case (90) , the clutch hub (10) and the clutch housing (20) have a common central axis.

11. The lubrication system for multiplate wet clutch assembly as claimed in claim 10, wherein
- the clutch hub (10) has a gear (12) on its curved outer surface extending outwards from center of the cover plate (80);
- the clutch hub (10) is supported on the coaxial inner boss (14) through bushes given on outer surface of the coaxial inner boss (14);
- the clutch hub (10) has oil flow openings (16) adjacent to the gear (12) on its curved outer surface extending outwards from the cover plate (80) that constitutes an oil flow channel with a clearance space given between said clutch hub (10) and an inner boss (14) and which terminates at oil flow openings (18) given at the curved outer surface of said clutch hub (10) on which the plurality of clutch plates (40) are mounted;
- the oil flow openings (18) and a set of openings (52) provided along the inner curved surface of the pressure plate (50) along with the plurality of clamping springs (60) and the openings (22) on the clutch housing (20) constitute another oil flow channel for supplying oil to the stack of plurality of friction and clutch plates (30 and 40); and
- the clutch housing (20) on which the plurality of friction plates (30) are mounted has oil flow openings (25) on its curved inner surface that constitute an oil evacuation path for the oil supplied to the stack of plurality of friction and clutch plates (30 and 40).

Dated this 28th day of February 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
“LUBRICATION SYSTEM FOR MULTIPLATE WET CLUTCH ASSEMBLY 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 multiplate wet clutches provided in motor vehicles. More particularly, it relates to the lubrication and cooling system of the clutch assembly by forming an optimized lubrication fluid flow path between the clutch housing and clutch outer case.

Background of the Invention

[002] Conventional multiplate wet clutch provide pathways for lubricant to be circulated within the clutch housing so as to lubricate and take away heat generated by the frictional interaction between the clutch plates and the friction plates. In these multiplate wet clutch once the lubrication fluid leaves the clutch housing, the lubrication fluid exiting under the effect of centrifugal force continues to move along the wall of the cover surrounding the clutch. This reduces the effectiveness of lubrication system within the clutch unless this fluid is intercepted and pumped back into the conventional multiplate wet clutch using a finite amount of engine power. This may also make it essential to maintain high level of lubrication fluid in the storage reservoir at all times.

[003] Some of the known solutions to this problem involve using means such as a wiper for collecting lubricating fluid directly from the openings given on the clutch housing and then recirculating it using a pump linked to rotating sub-components of the clutch. These features may end up reducing both the time and the surface area available for heat rejection for the lubrication fluid; thereby causing faster rise in lubrication fluid temperatures during periods of excessive clutch operation by the motor vehicle user. Existence of such issues may necessitate either maintenance of a large reservoir of lubrication fluid to act as a heat sink or provision of other active/passive heat rejection features for maintaining lubricant temperature within acceptable limits or both.

[004] Alternatively, conventional solutions not involving use of pumps try to disrupt the flow of lubricating fluid and deposit it in a collection space given along the central axis of the multiplate wet clutch assembly. This allows the lubrication fluid to be recirculated towards the stack of clutch and friction plates under the effect of centrifugal force without using any additional pumps. But these features aren’t always effective in maintaining sufficient supply of the lubrication fluid around all the sub-components provided in the multiplate wet clutch assembly. As such, lack of proper lubrication fluid flow can eventually cause the properties of such sub-components to change undesirably under the effect of heat that is not evacuated from the multiplate wet clutch assembly. More specifically, it is the clamping springs need to be properly lubricated and kept sufficiently cool as heat generated by frictional interaction of clutch and friction plates can cause the spring constant to decrease.

[005] Therefore given the known limitations of conventional solutions, there exists a long pending unmet need for providing a lubrication and cooling system for multiplate wet clutch assemblies that ensure an optimized and well distributed flow of lubricating fluid within themselves without using any additional component and/or power consuming features for recirculation of the lubricating fluid.

Objectives of the Present Invention

[006] The main object of the present invention is to provide a lubrication system for multiplate wet clutch assembly of a vehicle.

[007] Another objective of the present invention is to provide a lubrication system for multiplate wet clutch assembly that ensures effective lubrication of all of its sub-components.

[008] Yet another objective of the present invention is to provide a lubrication system for multiplate wet clutch assembly that does not require any additional component and/or power consuming features for effectively recirculating the lubrication fluid.

[009] Still another objective of the present invention is to provide a lubrication system for a multiplate wet clutch assembly that does not draw any additional power to ensure effective lubrication fluid recirculation.

[0010] Yet, further objective of the present invention is to provide a lubrication system for a multiplate wet clutch assembly wherein the outer surface of the clutch housing and inner surface of the clutch outer cover has uniquely profiled ribbing pattern that formulate continuous flow passage for the lubrication fluid.

[0011] Further the objective of the present invention is to provide a lubrication system for a multiplate wet clutch assembly that provides sufficient time and surface area for the lubricant fluid to reject its heat before being recirculated.
Brief Description of Drawings

[0012] 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

[0013] Figure 1 discloses the cut sectional view of the multiplate wet clutch assembly in accordance with the present invention.

[0014] Figure 2 shows the perspective view of the clutch outer case of the clutch assembly as per the present invention.

[0015] Figure 3 presents the exploded view of a curved projection provided on the inner surface of the clutch outer case as per the invention.

[0016] Figure 4a shows the front view of the clutch outer case and Figure 4b shows the cut-sectional view taken at A-A of the clutch outer case in accordance with the present invention.

[0017] Figure 5 discloses perspective view of the clutch outer case cut at its corner to clearly show the ribs provided on the inner surface thereof.

[0018] Figure 6b presents the rear view of the clutch housing and Figure 6a shows the cut sectional view taken at H-H of the clutch housing in accordance with the present invention.
[0019] Figure 7 shows the perspective view of the clutch housing taken from rear side as per the present invention.

[0020] Figure 8 shows the enlarged view showing the overlap of curved projection on the clutch outer case with the circular rib on the clutch housing in accordance with the present invention.

Detailed Description of the Present Invention

[0021] 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.

[0022] In accordance with the disclosed preferred embodiment of the invention, a lubrication system for multiplate wet clutch assembly of a vehicle comprising of a clutch housing (20) having a clutch hub (10), a plurality of friction plates (30), a plurality of clutch plates (40), a pressure plate (50), a plurality of clamping springs (60), a belleville spring (70) and a cover plate (80) encompassed therein; and a clutch outer case (90). The clutch outer case (90) is mounted on the transmission case by using conventional fastening means such as bolts.

[0023] The clutch housing (20) has a circular rib (24) on the outer flat surface (23) projecting out at outer periphery of said outer flat surface (23) and encircling a plurality of openings (22) of the clutch housing (20) from the outside. The clutch outer case (90) is configured to have at least three ribs (92) and a curved projection (94) on its inner surface. The ribs (92) are spaced apart by an angular distance (a) and originate at the edge of the central hole (96) of the clutch outer case (90) and proceed radially outward and then along the inner curved surface of the clutch outer case (90). The curved projection (94) on the inner surface of the clutch outer case (90) has a scoop profile and is positioned opposite to the ribs (92) at a location below the central hole (96) of the clutch outer case (90). When the vehicle is operating, the centrifugal force acts upon the lubrication fluid and causes it to flow along the walls of the clutch outer case (90). The ribs (92) and the curved projection (94) on the clutch outer case (90) and the circular rib (24) on the clutch housing (20) work together to form the flow passage and direct the lubrication fluid towards the plurality of openings (22) after having disrupted the flow that was happening under the influence of centrifugal force (refer Figs. 1, 2, 4 & 5).

[0024] The clutch housing (20) is generally mounted on the engine output shaft or gearbox input shaft depending on the vehicle architecture. In the present invention the clutch housing mounted on an engine output shaft through the clutch hub (10) is positioned inside the clutch outer case (90) in such way that the clutch hub (10), the clutch housing (20) and the clutch outer case (90) are coaxial. The curved projection (94) of the clutch outer case (90) overlaps with the circular rib (24) of the clutch housing (20) from its inner side so as to make a hydraulic communication with the openings (22) of the clutch housing (20) to form an optimized lubrication flow path for the clutch assembly. The overlapping (M’) of the curved projection (94) with the circular rib (24) ensures that the lubrication fluid whose flow under the influence of centrifugal force has been disrupted is directed directly at the mouth of the plurality of opening (22) (refer Figs. 1, 6 & 7).

[0025] The clutch housing (20) encompasses the clutch hub (10) in a manner such that at least one portion of the clutch housing (20) is mounted and supported coaxially upon a coaxial inner boss (14) of the clutch hub (10) via bush located between said clutch housing (20) and said coaxial inner boss (14). A plurality of friction plate (30) are mounted on the clutch housing (20) and a plurality of clutch plates (40) are mounted on the clutch hub (10) in a manner such that said plurality of friction plates (30) and said plurality of clutch plates (40) are positioned alternatively with each other thereby forming a stack of plurality of friction and clutch plates (30 and 40). A pressure plate (50) is mounted and supported coaxially upon the coaxial inner boss (14) of the clutch hub (10) in a manner such that one surface of said pressure plate (50) pushes against the last of the clutch plates (40) and locates one end of plurality of clamping springs (60) in spring seat formed on the other surface of said pressure plate (50). The belleville spring (70) is positioned within a circular groove given on one surface of the said pressure plate (50) such that said belleville spring (70) is located between the last of the plurality of clutch plates (40) and the pressure plate (50). The other end of plurality of clamping springs (60) is located in spring seats given on flat inside surface of the clutch housing (20), the spring seats so provided on the flat inside surface of the clutch housing (20) have openings (22) located along the central axis of plurality of clamping springs (60), a circular rib (24) projecting out the outer flat surface (23) of the clutch housing (20) encompasses the openings (22) from the outside. The clamping springs (60) work by exerting a force upon the friction and clutch plates (30 and 40) via the pressure plate (50) to ensure that they come together and stop slipping against each other once the vehicle user’s action cause the clutch to engage. The Belleville spring (70) as provided in the multiplate wet clutch prevents oscillation of torque output from the multiplate wet clutch by providing a reaction force that resists force acting via the pressure plate (50). Furthermore, given that the openings (22) are adjacent to the base of the clamping springs (60), this ensures that the lubrication fluid directed at the plurality of openings (22) reaches the clamping springs (60) to cool and to lubricate them.

[0026] The cover plate (80) is mounted and fixed on the clutch housing (20) in manner such that said cover plate (80) closes an open end of the clutch housing (20). The clutch outer case (90) surrounds the unit formed by the clutch hub (10), the clutch housing (20) and the components provided therein in such way that the clutch outer case (90), the clutch hub (10) and the clutch housing (20) have a common central axis.

[0027] The clutch hub (10) has a gear (12) on its curved outer surface extending outwards from center of the cover plate (80). The gear (12) is in contact with another gear (not shown in the diagrams) which takes the torque output from the clutch hub (10) to the gear box of the vehicle. The clutch hub (10) is supported on the coaxial inner boss (14) through bushes given on outer surface of the coaxial inner boss (14). The clutch hub (10) has oil flow openings (16) adjacent to the gear (12) on its curved outer surface extending outwards from the cover plate (80) that constitutes an oil flow channel with a clearance space given between said clutch hub (10) and an inner boss (14) and which terminates at oil flow openings (18) given at the curved outer surface of said clutch hub (10) on which the plurality of clutch plates (40) are mounted. The lubrication oil is introduced into the multiplate wet clutch through this oil flow channel. Its flow follows the direction as shown by the arrows shown in Fig. 1. The oil flow openings (18) and a set of openings (52) provided along the inner curved surface of the pressure plate (50) along with the plurality of clamping springs (60) and the openings (22) on the clutch housing (20) constitute another oil flow channel for supplying oil to the stack of plurality of friction and clutch plates (30 and 40). The arrows shown in Fig. 1 indicate the flow through the oil flow channel formed by these features. The clutch housing (20) on which the plurality of friction plates (30) are mounted, has oil flow openings (25) on its curved inner surface that constitute an oil evacuation path for the oil supplied to the stack of plurality of friction and clutch plates (30 and 40) (refer Fig. 1).

[0028] The curved projection (94) is so positioned on the inner surface of the clutch outer case (90) that the either extreme corners of the curved projection (94) makes an angle (ß) with the center point of the origin of the center rib (92b) to hydraulically communicate with the openings (22) given on the clutch housing (20) (refer Fig. 1). The angle (ß) is in the range of 25 to 110 degree. This angle is significant because it ensures that the oil flow disrupted by the ribs (92) is deposited upon the curved projection (94). The best optimized range of the angle (ß) with respect to the preferred orientation of the ribs is 72 to 95 degree. As the angle (a) between two successive ribs increases, the angle (ß) also increases in the proportion to provide an optimized and efficient lubrication system. Thus, the relation of angle (a) made by two successive ribs on the inner surface of the clutch outer case (90) with angle (ß) made by the extreme edges of the curved projection with the central rib (92) is ß = 2.6a.

[0029] The curved projection (94) of the clutch outer case (90) has at least an opening (98) at each of its longitudinal ends. These openings (98) allow excess lubricating fluid to drain out before it enters the multiplate wet clutch thereby preventing its flooding with lubricating oil when the vehicle is under operation. The diameter of the openings (98) provided on the curved projection (94) is in the range of 0.15 to 0.25 times of the height (H) of the curved projection (94).
[0030] The outer case (90) has strengthening ribs (93) of different lengths projecting out of its inner surface of the clutch outer case (90) along the outer edge of to the central hole (96) for enhancing structural strength of the outer case (90) (refer Fig. 2). These ribs function primarily to give structural strength to the clutch outer case (90). The main function of the uniquely profiled ribs (92) is to capture the lubrication oil and direct it on the curved projection (94) for recirculation for lubrication. The angular distance (a) between the successive two ribs (92) is in the range of 15 to 45 degree. The significance of this angle is that it spreads out the ribs (92) thereby allowing them to be more effective in their function of capturing the oil and disrupting flow of lubrication oil along the walls of the clutch outer case (90) and then directing it to the curved projection (94) located below the ribs (92). The best results by the ribs for capturing the oil and then directing it on the curved projection (94) for the effective lubrication and optimized fluid flow path is obtained with the ribs orientation wherein the successive ribs are spaced apart by an angular distance (a) of 27 to 34 degree. The cross sectional profile of the ribs (92) is selected from a set of profiles of rectangle, rectangle with chamfered corners and right trapezoid. The height (h) of the ribs (92) is in the range of 0.05 to 0.10 times of the inner radius (Rc) of the clutch outer case (90). The ribs (92) besides performing the primary function of capturing the oil and directing the flow of lubrication oil also have a secondary function of giving structural strength to the clutch outer case (90). The range as disclosed above ensures that ribs (92) are able to perform their stated functions.

[0031] The cross sectional profile of the circular rib (24) on the clutch housing (20) is selected from a set of profiles of a rectangle and right trapezoids. In case of a right trapezoid profiled rib (24) on the clutch housing the slope (?) of the slanting side of a right trapezoid is in the range of 3 to 5 degree. The height (h2) of the rib (24) is in the range of 0.12 to 0.25 times of the radius (Rh) of the circular rib (24). This range is significant because it helps to impart the desired overlap (M’) and ensure that the lubrication oil received on the curved projection (94) is effectively directed into the plurality of openings (22). The cross sectional profile of the curved projection (94) on the clutch outer case (90) is selected from a set of profiles of right trapezoid. The height (H) of the curved projection (94) is 0.4 to 0.6 times the inner radius (Rc) of the clutch outer case (90). Successful deposition of lubrication oil redirected by the ribs (92) is also dependent upon the range of this parameter i.e. the ratio of height (H) with respect to the inner radius of the clutch outer case (90). Following the given ratio allows the effect of lubrication oil splashing that happens due to the ribs (92) to be managed.

[0032] The overlap (M’) of the curved projection (94) of the clutch outer case (90) with the circular rib (24) of the clutch housing (20) is in the range of 40 to 60 per cent of the height (h2) of the circular rib (24) for the effective lubrication of the clamping springs (60) and optimized recirculation of the lubrication fluid. This range of overlapping is significant for the reason that it permits oil received on the curved projection (94) to be successfully redirected towards the plurality of openings (22).

[0033] The lubrication system formed by the disclosed constructional features begins working as soon as the lubricating oil flows into the oil flow openings (18). This happens after the vehicle user starts the vehicle. The lubrication oil then follows through the oil flow channels and towards the stack of friction and clutch plates (30 and 40) and then exits via the oil flow openings (25). After exiting the oil flow openings (25) the oil begins moving along the wall of the clutch outer case (90) till its flow is disrupted and redirected by the ribs (92) towards the curved projection (94). The oil while it is flowing over the clutch outer case (90) has the time and the surface to reject heat to the environment. From the curved projection (94), the lubrication oil moves towards and is deposited into the plurality of openings (22). The overlap (M’) between curved projection (94) and the circular rib (24) ensures that most of the lubricating fluid received on the circular rib (24) gets to pass through the openings (22). After entering through the openings (22) the lubricating oil flows over the plurality of clamping springs (60) and then through the openings (52) given on the pressure plate (50) towards the oil flow openings (18) and then back into the stack of friction and clutch plates (30 and 40).

[0034] When the clutch lever of a vehicle is actuated, an actuation rod causes the pressure plate (50) to be displaced further into the clutch housing (20). The displacement of the pressure plate (50) allows the friction and clutch plates (30 and 40) to move apart and separate (this is alternatively also identified by the phrase clutch disengagement). While the clutch is still disengaging, a lot of heat is generated when the plurality of friction and clutch plates (30 and 40) are still slipping over each other. When the plurality of friction and clutch plates (30 and 40) are still slipping, the frictional interaction generates heat which is evacuated by the lubricating oil flowing through the oil flow channels as detailed earlier in this specification. Once the separation of plurality of friction and clutch plate (30 and 40) is completed, torque transmission from the clutch housing (20) to the clutch hub (10) and then onto the gear box stops. As the pressure plate (50) is being displaced into the clutch hub (20), a reaction force is setup in the plurality of clamping springs (60) because of its compression.

[0035] When the user stops operating the clutch lever, the actuation rod returns to its original postion and the pressure plate (50) now moving under the reaction force exerted by the plurality of clamping spring (60) now causes the plurality of friction and clutch plates (30 and 40) to move closer and come into firm contact with each other. Before a firm contact is established between the plurality of friction and clutch plates (30 and 40), the slippage of friction and clutch plates (30 and 40) generate heat which is evacuated by the lubricating oil flowing through the oil flow channels as detailed earlier in this specification. Once firm contact is reestablished all torque received from the clutch housing (20) is transmitted to the clutch hub (10).

[0036] The lubrication system for multiplate wet clutch assembly formed by the constructional features of the clutch housing (20) and the clutch outer case (90) in accordance with the disclosed embodiment provides the following technical advantages:
- It ensures effective lubrication of all the clamping springs by recirculating the lubrication oil.
- It does not require any additional power consuming features for effectively dissipate the heat of lubricating oil and recirculating it in the lubrication system.
- It provides sufficient time and surface area for the lubricant fluid to reject its heat before being recirculated in the system.
- It does not draw any additional power to ensure effective lubrication recirculation of the lubrication oil.

[0037] The disclosed invention hence overcomes the limitation of the known solutions of existing lubrication systems for multiplate wet clutch assembly. The multiplate wet clutch assembly of a vehicle as described is mounted on the engine output shaft/gearbox input shaft. A person skilled in the art can change its mounting position without carrying out any significant change to the features of the multiplate wet clutch assembly. Hence, such changes in postion must not be viewed as taking the emerging variants/embodiments out of the scope of claims of the disclosed invention.

[0038] 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.