DESC: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
“MULTI-PLATE CLUTCH ASSEMBLY 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 the Invention

[001] The present invention is related to a multiplate clutch assembly for the two and three-wheeled vehicles. More particularly, the present invention is related to non-electric start (kick in case of two wheeler and lever in case of three wheeler) as well as electric start mechanism based two and three wheeled vehicles wherein said clutch assembly has an optimized and unique configuration of moving hub and fixed hub to have efficient lubrication and heat dissipation in the clutch assembly.

Background of the Invention

[002] A clutch device is positioned in a vehicle in between the engine and a driven body, particularly the transmission, to transfer or cut off the engine's rotational driving force to the driven body. The engagement of the clutch between the engine and the driven body 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, wear and tear of components, and serves as overload protection for the drivetrain.

[003] The conventional clutch devices generally comprise of a variety of arrangement of the number of clutch plates and friction plates, which are either brought into contact with each other or are separated from each other so that transfer of a rotational driving force from an engine to the transmission is allowed or blocked. However, such kind of arrangements in the clutch devices leads to generation of abnormal noise during power transmission and leads to non-uniform splash of lubricating oil in the stack of the friction and clutch plates. Additionally, the high friction between the clutch/steel plates and friction plates poses a durability problem.

[004] In order to fix the above mentioned problems and meet the need for a judder-free clutch, an assist and slip type clutch assemblies have been incorporated. The assist and slip clutch generally comprises of a fixed hub and a moving hub with a trapezoidal or triangular profiled structure thereon for torque transmission to the stack of friction plates and clutch plates. However, these types of clutches have limitations as these clutches are very much suitable for high performance bikes with electric start two wheelers. In case of automotive engines having kick in case of two wheelers and lever in case of three wheelers for cranking the engine of lower cc vehicles (lower than 125 cc), the assist and slip clutches with the slip function do not work upto the mark and are prone to the limitations. The slip function of the assist & slip clutch does not allow to start the engine because of slip mechanism of assist and slip clutch as it generates the wedging reaction between fixed slip side ramp and moving hub slip side ramp in opposite direction which causes the moving hub and fixed hub to move apart from each other and the clutch gets slipped instead of getting engaged as in this case slippage of clutch static torque is less.

[005] Hence, to address the above mentioned limitations of the clutch assemblies, there is a long pending unmet requirement to provide an improved clutch assembly with assist and assist feature for two and three wheeled vehicles that helps to boost up the static torque of the clutch, prohibit the clutch slip, and reduces the risk of clutch slippage while kicking the non-electric start (kick/lever start) as well as electric start (push button start) two and three-wheeled vehicles.
Objectives of the Present Invention

[006] The main objective of the present invention is to provide a multi-plate clutch assembly for a two and three wheeled vehicles.

[007] Another objective of the present invention is to provide a multi-plate clutch assembly with assist and assist feature for two and three wheeled vehicles that helps to boost up the static torque of the clutch.

[008] Yet, the objective of the present invention is to provide a multi-plate clutch assembly with assist and assist feature for two and three wheeled vehicles that prohibits the clutch slip, and reduces the risk of clutch slippage while kicking the non-electric start (kick/lever start) as well as electric start (push button start) two and three-wheeled vehicles.

[009] Yet, another objective of the present invention is to reduce the overall weight of the clutch assembly and thereby reduce the moment of inertia of complete clutch assembly on engine crank shaft.

[0010] Further objective of the present invention is to provide a clutch assembly with assist and assist feature for efficient torque transmission from the engine to the drive side in two and three wheeled vehicles.

[0011] Yet, the objective of the present invention is to provide a multiplate clutch assembly with optimized lubrication system that ensures efficient lubrication of plate stack and dissipation of heat in the clutch assembly by maintaining desired operating temperature throughout the clutch system.
[0012] Still, the objective of the present invention is to provide a clutch assembly with assist and assist feature that reduces the requirement of a high number of friction plates and steel plates in the plate stack of the clutch.

[0013] Still, another objective of the present invention is to provide a clutch assembly with enhanced factor of safety of the clutch by 15 – 20 % in both the directions viz. the driving side and kick side.

[0014] Further, another objective of the present invention is providing simple, cost effective, durable and easy to manufacture clutch assembly for two and three wheeled vehicles.

[0015] Yet, another objective of the present invention is to provide a clutch assembly which reduces the clutch lever effort.

Brief Description of the Drawings

[0016] This invention is illustrated in the accompanying drawings, throughout which like reference numerals and/or letters indicate the 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

[0017] Figure 1 discloses an exploded view of the clutch assembly in accordance with the present invention.

[0018] Figures 2a and 2b show the enlarged isometric views of the fixed hub of the present invention.
[0019] Figures 3a and 3b show the enlarged isometric views of curved helical ramp sliding surfaces of the fixed hub of the clutch assembly as per the present invention.

[0020] Figures 4a and 4b show the enlarged isometric views of the moving hub of the of the clutch assembly as per the present invention.

[0021] Figures 5a, 5b and 5c disclose the enlarged isometric views of uniquely profiled projections and its curved helical ramp sliding surfaces of the moving hub of the clutch assembly as per the present invention.

[0022] Figure 6a shows the sectional view of the moving hub and the fixed hub in engaged condition; and Figure 6b shows the enlarged view of contact surfaces of the moving hub and the fixed hub in engaged condition as per the present invention.

[0023] Figure 7a shows the sectional view of the moving hub and the fixed hub in disengaged condition; and Figure 7b shows the enlarged view of contact surfaces of the moving hub and the fixed hub in disengaged condition as per the present invention.

[0024] Figures 8a and 8b show the front and top views, respectively of the moving hub and the fixed hub in static condition as per the present invention.

[0025] Figures 8c and 8d show the views of the contact surfaces of the moving hub and the fixed hub in driving side assist condition and kick side assist condition, respectively in accordance with the present invention.

Detailed Description of the Present Invention

[0026] 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, the clutch assembly (100) for two and three wheeled vehicles comprises of a housing clutch assembly (10), a moving hub (20), a plate stack (30), a fixed hub (40), a compression spring (50), a holder plate (60) and a plurality of bolts (70). The plate stack (30) comprises of friction plates (30A) and clutch plates / metal plates (30B) arranged alternatively. Each of the friction plates (30A) has a plurality of friction petals (310) affixed equidistant from each other over its radial surface and a plurality of claws (315) on its outer periphery so as to get it fitted in the clutch housing (110). Each of the clutch plates (30B) is configured to have a plurality of splines (30BT) on its inner peripheral surface so as to get it engaged with the splines of the moving hub.

[0027] The housing clutch assembly (10) comprises of a primary gear (105) and a clutch housing (110). The primary gear (105) is fitted at the back side of the clutch housing (110) with the help of suitable fastening means so as to make it an integrated housing clutch assembly (10). The primary gear (105) receives the torque from an output shaft of an engine (not shown in the figure) and transfers the torque to the housing clutch (110) through a damping system (not shown in the figure) positioned in the primary gear (105). The housing clutch (110) is configured to have a plurality of slotted windows (115) for receiving the claws (315) of the friction plates (30A).

[0028] Referring to Figs. 4a and 4b, the moving hub (20) is configured to have a resting face (RF1) with an opening (20a) at the center, a plurality of uniquely profiled projections (21), and extruded splined profile (20S) projecting out orthogonally from the resting face (RF1) along the central opening (20a). A plurality of uniquely profiled projections (21) are integrated with the resting face (RF1) along the central opening (20a) of the moving hub (20) in such a way that they are projecting out orthogonally from the resting face (RF1) of the moving hub (20). The said profiled projections (21) are positioned around the central opening (20a) in such way that they are equidistant from each other by an angular distance ranging from 72 to 120 degrees. The most optimized arrangement is of at least three profiled projections (21) spaced apart by an angular distance of 120 degrees. The said projections (21) are joined with each other by an extruded splined profile (20S) along the central opening (20a) and said splined profile (20S) has a plurality of teeth (20ST) on its outer peripheral surface. The teeth (20ST) given on the extruded splined profile (20S) are of uniform height. However, the teeth given at the central portion (20SC) of the extruded splined profile (20S) are extended out by (E) than that of the teeth on its either sides. The extension (E) of the teeth on extruded splined profile (20S) is at least equal to total of thickness of a friction plate (30A) and a metal / clutch plate (30B). The teeth given at the central portion (20SC) of the extruded splined profile (20S) is provided to guide the friction and metal plates (30B) with the moving hub (20) in disengaged condition and thereby prevent the fall out of the plates (30A and 30B) from the splined profile (20S) of the moving hub (20).

[0029] Referring to Figs. 4a, 4b, 5a, 5b and 5c, said projections (21) are configured to have V-profiled base (21A) and cylindrical top (21B). The V-profiled base (21A) of the projection (21) has a curved helical ramp sliding surfaces (24A, 24B) on its either side. The cylindrical top (21B) has a threaded groove (21BT) on its top surface (21T). Further, the moving hub (20) is configured to have an oil gateway (20G), an oil reservoir pocket (20RP) formed in the V-profiled base (21A), and a profiled opening (20D) provided on the resting face (RF1) in between two successive projections (21) along the central opening (20a) inside the extruded splined profile (20S) of the moving hub (20). The oil gateway (20G) is provided for receiving the excess oil from the fixed hub (40) and the oil reservoir pocket (20RP) is provided for storing the excess oil. The oil gateway (20G) and the oil reservoir pocket (20RP) together are configured to keep the curved helical ramp surfaces of the projection (21) lubricated so as to maintain the desired operating temperature. The number of profiled openings (20D) on the moving hub (20) is at least three and these openings (20D) works as the passage for draining the excess oil from the stack (30) of the friction plates (30A) and steel / clutch plates (30B).

[0030] Referring to Figs. 2a, 2b, 3a and 3b, the fixed hub (40) is configured to have a boss (40S), a resting face (RF2), at least three uniquely profiled cavities (40C) and at least three pairs of curved helical ramp sliding surfaces (40A and 40B). The profiled cavities (40C) are formed with curved helical ramp sliding surfaces (40A and 40B) and the resting face (RF2). These cavities (40C) of the fixed hub (40) are configured to receive the projections (21) of the moving hub (20) during assembly of the clutch of the present invention. This unique meshing, i.e. the wedge action of the sliding surfaces (40A and 40B) of the fixed hub (40) with the curved helical ramp sliding surfaces (24A, 24B) of the moving hub (20) gradually generates the axial thrust (i.e. assist load) in both directions viz. driving side and kick side. When the clutch assembly rotates in anticlockwise direction, the sliding surface (40A) of the fixed hub (40) generates the wedge action with the sliding surface (24B) of the moving hub (20); and when the clutch assembly rotates in clockwise direction, the sliding surface (40B) of the fixed hub (40) generates the wedge action with the sliding surface (24A) of the moving hub (20).
[0031] Further, the fixed hub (40) is configured to have a plurality of U-profiled pocket (40U) in between two successive cavities (40C) of the fixed hub (40), and said profiled pocket (40U) is configured to have a tub shaped oil reservoir (40T) and an excess oil gateway (40TG). The profiled pocket (40U) passes the oil to the tub shaped oil reservoir (40T) which then passes the excess oil out of the plate stack (30) through the oil gateway (40TG) due to the centrifugal action. The oil from the oil reservoir pocket (40T) of the fixed hub (40) is transferred to the oil reservoir (20RP) of the moving hub (20) so as to make the seamless circulation of oil to keep the helical ramp surfaces of the moving hub and fixed hub lubricated. The boss (40S) of the fixed hub (40) has a plurality of splines on its internal peripheral surface as shown in Fig. 2 so at to get fitted on the input shaft of the transmission (gear box) during the assembly of the clutch. The boss (40S) of the fixed hub (40) is guided in the central opening (20a) of the moving hub (20) to have axial alignment of the moving hub (20) with the fixed hub (40) and also to avoid tilting of the moving hub (20) during the disengaged condition of the clutch.

[0032] The plate stack (30) comprises multiple friction plates (30A) and clutch plates (30B) which are stacked alternatively to form the plate stack. During assembly of the plate stack (30) over the extruded splined profile (20S) of the moving hub (20), the splines (30BT) of the clutch plates (30B) are getting meshed with the splines provided on the extruded splined profile (20S) of the moving hub (20). Thus the plate stack (30) gets mounted on the extruded splined profile (20S) of the moving hub (20) and is sandwiched between the resting face (RF1) of the moving hub (20) and the resting face (RF2) of the fixed hub (40). The claws (315) of the friction plates (30A) are engaged inside the respective slotted windows (115) of the housing clutch (110). The arrangement of the plate stack (30), housing clutch (110) and the moving hub (20) is responsible for torque transmission from the housing clutch assembly (10) to the fixed hub (40). Thus, the torque is transferred from the housing clutch (110) to the fixed hub (40) through the moving hub (20) due to the axial load of a compression spring (50).

[0033] During the assembly of the moving hub (20) with the fixed hub (40), each of the cylindrical top (21B) of the projection/s (21) of the moving hub (20) passes through the cavities (40C) of the fixed hub (40). The compression spring (50) is positioned within a spring seat (48) provided in the fixed hub (40) and the spring seat in the holder plate (60). The holder plate (60) has a plurality of holes (60H) on its periphery and the bolts (70) passes through these holes are configured to get received and threaded there in the threaded groove (21BT) of the projection (21) of the moving hub (20). Thus, the holder plate gets locked with the moving hub (20) at its projections (21) to generate the axial clamp load by the compression spring (50).

[0034] The above assembly of moving hub (20), plate stack (30), fixed hub (40), and the holder plate (60) along with the compression spring (50) is housed inside the housing (110) of the housing clutch assembly (10). The primary gear (105) of the housing clutch assembly (10) receives the torque from the output shaft / crankshaft of the engine and transfers the torque to the housing clutch (110) through the damping system (not shown in the figure) and further this torque is being transferred to the plate stack (30). Then the torque is transferred to the moving hub due to assembly of compression spring which generates axial load on the plate stack. This leads to transfer of torque from moving hub to fixed hub. Finally, the torque gets transferred from fixed hub to the transmission through the transmission shaft that gets fitted in the boss of the fixed hub through meshing splines.
[0035] The holder plate (60) compresses the compression spring (50) in such a manner as to achieve the desired pressure on the plate stack (30) to transmit the torque from engine to the transmission of the vehicle.

[0036] Referring to Fig. 8c, in the drive assist mode (i.e. the torque is being transferred from engine to transmission), the clutch assembly of the present invention rotates in anticlockwise direction. At this moment, the curved helical assist ramp (24B) of the moving hub (20) slides over the curved helical ramp surface (40A) of the fixed hub (40). This sliding of the ramp surfaces increases the normal reaction (i.e. wedge reaction) which consequently results into increase in pressure on the plate stack (30). This consequently increases the torque transmission capacity and factor of safety of the clutch. The increase in normal reaction on account of ramps (24B, 40A) is directly proportional to engine torque. For a given factor of safety, the assist ramp (24B) helps to reduce the efforts by 15- 35 % on the clutch lever mounted on the handle bar of a vehicle.

[0037] Referring to Fig. 8d, in coasting side assist mode (i.e. when kicking the vehicle for starting the engine), the curved helical assist ramp (24A) of the moving hub (20) slides over the curved helical ramp surface (40B) of the fixed hub (40). This sliding of the ramp surfaces increases the normal reaction which consequently results into the increase in pressure on the plate stack (30). This aids in drastically reducing the cranking / kicking efforts in case of the non-electric engine start vehicles (kick in 2-wheeler and handle lever in a 3-whheeler / rickshaw). In case of electric start (push button) engine, it drastically reduces the efforts on the start motor.

[0038] Thus, in both the modes (i.e. driving mode and coasting mode), the clutch assembly of the invention works efficiently with sufficient lubrication as the ample amount of oil is circulated via the oil circulation gateway (40U). The oil reservoir (40T) of the fixed hub (40) is profiled in such way that it maintains the minimum oil required for the efficient lubrication of the plate stack (30). The slanted wall (SW) of the excess oil gateway (40TG) makes an angle a with the vertical to have effective splashing of the oil needed the lubrication and heat dissipation from the clutch assembly. The angle a made by the slanting wall (SW) of the excess oil gateway (40TG) ranges from 15 to 45 degrees from the vertical. This is the most optimized range of angle to have efficient lubrication and the heat dissipation.

[0039] Referring to Fig. 8a, in the coasting mode, the radius of curvature (CMKR, CFKR) of the sliding ramp surface (24A, 40B) of the moving hub (20) and the fixed hub (40) is equal to K multiplied by the width (W) of protrusion/ramp surface, wherein K is the multiplying factor varying from 412.0 to 816.0. The CMKR is the radius of curvature of the ramp of the moving hub, and CFKR is the radius of curvature of the ramp of the fixed hub. In the drive mode, the radius of curvature (CMAR, CFAR) of the sliding ramp of the moving hub and fixed hub is equal to P multiplied by the width (W) of protrusion/ramp surface, wherein P is the multiplying factor varying from 422.0 to 1016.0. The CMAR is the radius of curvature of the ramp of the moving hub, and CFAR is the radius of curvature of the ramp of the fixed hub.

[0040] Referring to Figs. 6a, 6b, 7a and 7d, the radius of curved helical ramp (40A, 40B, 24A, 24B) has to be as mentioned above in order to have desired contact surface (S1) centralized on the width of ramp (W) (during initial engagement) followed by widening of contact across the width (W) of the ramp. During initial engagement condition of the radius of curved helical ramp (40A, 40B, 24A, 24B), the contact surface (S2) will be less as compared to the contact surface (S1), where the contact surface (S1) is achieved when the plate stack (30) is fully in engaged condition. This ensures gradual engagement of ramp surfaces (40A, 40B, 24A, 24B) thus reducing the wear of ramp surfaces of the moving hub (20) and the fixed hub (40) which aids in improving the life of the clutch assembly with reduction in judder and rattling.

[0041] For functioning of the clutch assembly as per the intent of the present invention, there should a functional gap (G) in a specific range. In case of drive mode, the functional gap (G) is in kick side as shown in Fig. 8c, and in case of coasting mode, the functional gap (G) is in drive side as shown in Fig. 8d. If the functional gap (G) is less than the specific range with respect the outer diameter of the friction plate (30A), the clutch will not work in the assist side leading to structural damage of the ramp surfaces (40A, 24B). If the functional gap is more than the specific range with respect to the outer diameter of the friction plate (30A), the clutch will work in the assist side leading high intensity mechanical noise, making the noisy clutch and creating the micro cracks in the helical ramp geometry which is not accepted for the vehicles. Therefore, the most optimized range of the functional gap (G) in the present invention varies from 2.6 to 4.0 mm.

[0042] Referring to Fig. 8b, the crowning radius (CTMAR) of the helical sliding ramp of the moving hub (20) and crowning radius (CTFAR) of the helical sliding ramp of the fixed hub (40) are variable with respect to the maximum disengage stroke length through a multiplying factor (Q) and said factor (Q) varies from 643.0 to 725.0. Due to this radius the contact patch of assist surface gets centralized which gives the better performance and better life of the clutch.
[0043] The multiplate clutch assembly of the present invention in accordance with the discussed embodiment provides the following technical advantages that contribute to the technical advancement of the clutch assembly (100) for two and three-wheeled vehicles.
- The curved helical ramp profile of the moving hub and fixed hub increases the normal reaction at the friction stack (30) interface for improved frictional torque transmission capacity of the clutch assembly in both the directions, drive and coasting as well.
- The uniquely profiled projections (21) of the moving hub (20) causes reduction in the weight of the clutch assembly and the inertial effect of the clutch.
- It provides optimized and efficient lubrication which results in enhanced life of the clutch assembly.
- The clutch assembly of the invention leads to drastic reduction in cranking efforts.
- The invention provides the clutch assembly with no judder, vibrations and unwanted noise.
- The unique arrangement of profiled fixed hub and moving hub increases the static slip torque capacity of the clutch.
- It provides the clutch assembly for two and three wheeled vehicles with enhanced factor of safety of the clutch by 15 – 20 % in both the directions viz. the driving side and kick side.
- The clutch assembly of the invention is simple in construction, cost effective, durable and easy to manufacture.

[0044] The foregoing description of the specific embodiment of the invention will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments 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 embodiments. 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.

,CLAIMS:We Claim:

1. A multiplate clutch assembly (100) for two and three wheeled vehicles comprising of a housing clutch assembly (10), a moving hub (20), a plate stack (30), a fixed hub (40), a compression spring (50), a holder plate (60) and a plurality of bolts (70); wherein,
- the moving hub (20) is configured to have a resting face (RF1) with an opening (20a) at the center, a plurality of uniquely profiled projections (21) spaced apart from each other by an angular distance of 72 to 120 degrees, an oil gateway (20G), an oil reservoir pocket (20RP), and extruded splined profile (20S) projecting out orthogonally from the resting face (RF1) along the central opening (20a);
- the fixed hub (40) is configured to have a boss (40S), a resting face (RF2), at least three uniquely profiled cavities (40C), at least three pairs of curved helical ramp sliding surfaces (40A and 40B), U-profiled pocket (40U) having a tub shaped oil reservoir (40T) in between two successive cavities (40C), and an excess oil gateway (40TG);
- the plate stack (30), comprising of friction plates (30A) and clutch plates / metal plates (30B) arranged alternatively, is mounted on the extruded splined profile (20S) of the moving hub (20) and is sandwiched between the resting face (RF1) of the moving hub (20) and the resting face (RF2) of the fixed hub (40);
- the projection/s (21) of the moving hub (20) are configured to pass through the cavities (40C) of the fixed hub (40);
- the compression spring (50) is positioned within a spring seat (48) provided in the fixed hub (40) and the spring seat provided in the holder plate (60); and
- the holder plate (60) has a plurality of holes (60H) on its periphery, and the bolts (70) are configured to pass through holes (60H) to get received and threaded there in the projection (21) of the moving hub (20) locking the holder plate (60) with the moving hub (20) at its projections (21) to generate the axial clamp load by the compression spring (50).

2. The multiplate clutch assembly (100) as claimed in claim 1, wherein
- the uniquely profiled projections (21) are integrated with the resting face (RF1) along the central opening (20a) of the moving hub (20) in such a way that they are projecting out orthogonally from the resting face (RF1) of the moving hub (20);
- said profiled projections (21) are positioned around the central opening (20a) and are equidistant from each other by an angular distance ranging from 72 to 120 degrees;
- the said projections (21) are joined with each other by an extruded splined profile (20S) along the central opening (20a) and said splined profile (20S) has a plurality of teeth (20ST) on its outer peripheral surface; and
- the teeth (20ST) given on the extruded splined profile (20S) are of uniform height.

3. The multiplate clutch assembly (100) as claimed in claim 2, wherein
- the teeth given at the central portion (20SC) of the extruded splined profile (20S) are extended out by (E) than that of the teeth on its either sides; and
- the extension (E) of the teeth on extruded splined profile (20S) is at least equal to total of thickness of a friction plate (30A) and a metal / clutch plate (30B) to guide the friction and metal plates (30B) with the moving hub (20) in disengaged condition and thereby prevent the fall out of the plates (30A and 30B) from the splined profile (20S) of the moving hub (20).

4. The multiplate clutch assembly (100) as claimed in claim 3, wherein
- the projections (21) of the moving hub (20) are configured to have V-profiled base (21A) and cylindrical top (21B);
- the V-profiled base (21A) of the projection (21) has a curved helical ramp sliding surfaces (24A, 24B) on its either side; and the cylindrical top (21B) has a threaded groove (21BT) on its top surface (21T);
- said moving hub (20) is configured to have an oil gateway (20G) and an oil reservoir pocket (20RP) formed in the V-profiled base (21A), and a profiled opening (20D) provided on the resting face (RF1) in between two successive projections (21) along the central opening (20a) inside the extruded splined profile (20S) of the moving hub (20);
- the oil gateway (20G) is configured to receive the excess oil from the fixed hub (40) and the oil reservoir pocket (20RP) is configured to store the excess oil; said oil gateway (20G) and said oil reservoir pocket (20RP) together are configured to keep the curved helical ramp surfaces of the projection (21) lubricated so as to maintain the desired operating temperature; and
- the number of profiled openings (20D) on the moving hub (20) is at least three and these openings (20D) are configured to drain the excess oil from the stack (30) of the friction plates (30A) and steel / clutch plates (30B).
5. The multiplate clutch assembly (100) as claimed in claim 1, wherein
- the profiled cavities (40C) of the fixed hub (40) are formed within the curved helical ramp sliding surfaces (40A and 40B) and the resting face (RF2); and said cavities (40C) are configured to receive the projections (21) of the moving hub (20) of the multiplate clutch (100); and
- the wedge action of the sliding surfaces (40A and 40B) of the fixed hub (40) with the curved helical ramp sliding surfaces (24A, 24B) of the moving hub (20) are configured to gradually generate the axial thrust (i.e. assist load) in both directions viz. driving side and kick side.

6. The multiplate clutch assembly (100) as claimed in claim 5, wherein
- the fixed hub (40) is configured to have a plurality of U-profiled pocket (40U) in between two successive cavities (40C) of the fixed hub (40), and said profiled pocket (40U) is configured to have a tub shaped oil reservoir (40T) and an excess oil gateway (40TG);
- said profiled pocket (40U) is configured to pass the oil to the tub shaped oil reservoir (40T) which is further configured to pass the excess oil out of the plate stack (30) through the oil gateway (40TG) due to the centrifugal action; and
- the oil reservoir pocket (40T) of the fixed hub (40) is configured to transfer the oil to the oil reservoir (20RP) of the moving hub (20) so as to make the seamless circulation of oil to keep the helical ramp surfaces of the moving hub and fixed hub lubricated.

7. The multiplate clutch assembly (100) as claimed in claim 6, wherein
- the excess oil gateway (40TG) is configured to have a slanted wall (SW) and said wall (SW) makes an angle a with the vertical to have effective splashing of the oil needed the lubrication and heat dissipation from the clutch assembly; and
- said angle a made by the slanting wall (SW) of the excess oil gateway (40TG) ranges from 15 to 45 degrees from the vertical.

8. The multiplate clutch assembly (100) as claimed in claim 6, wherein
- the fixed hub (40) has the boss (40S) with a plurality of splines on its internal peripheral surface so as to get fitted on the input shaft of the transmission (gear box); and
- said boss (40S) of the fixed hub (40) is configured to get guided in the central opening (20a) of the moving hub (20) to have axial alignment of the moving hub (20) with the fixed hub (40) and to avoid tilting of the moving hub (20) during the disengaged condition of the clutch.

9. The multiplate clutch assembly (100) as claimed in any of the claims 4 and 6, wherein
- the ramp (24A) of the moving hub (20) is configured to have radius of curvature (CMKR) and the ramp (40B) of the fixed hub (40) is configured to have radius of curvature (CFKR) during the coasting mode; and said radii of curvature (CMKR, CFKR) of the sliding ramp surface (24A, 40B) of the moving hub (20) and the fixed hub (40) is equal to K multiplied by the width (W) of protrusion/ramp surface, wherein K is the multiplying factor varying from 412.0 to 816.0; and
- the ramp (24B) of the moving hub (20) is configured to have radius of curvature (CMAR) and the ramp (40A) of the fixed hub (40) is configured to have radius of curvature (CFAR) during the driving mode; and said radii of curvature (CMAR, CFAR) of the sliding ramp surface (24B, 40A) of the moving hub (20) and the fixed hub (40) is equal to P multiplied by the width (W) of protrusion/ramp surface, wherein P is the multiplying factor varying from 422.0 to 1016.0.

10. The multiplate clutch assembly (100) as claimed in any of the claims 4 and 6, wherein
- the helical sliding ramp (24A, 24B) of the moving hub (20) is configured to have a crowning radius (CTMAR) and the helical sliding ramp (40A, 40B) of the fixed hub (40) is configured to have a crowning radius (CTFAR) so as to centralize the contact patch of assist surface; and
- said crowing radii (CTMAR, CTFAR) are configured to vary with respect to the maximum disengaged stroke length through a multiplying factor (Q) and said factor (Q) varies from 643.0 to 725.0.

11. The multiplate clutch assembly (100) as claimed in any of the claims 9 and 10, wherein
- the sliding ramp surface (40B) of the fixed hub (40) and the sliding ramp surface (24A) of the moving hub (20) are configured to form a functional gap (G) towards the coasting side in the drive mode;
- the sliding ramp surface (40A) of the fixed hub (40) and the sliding ramp surface (24B) of the moving hub (20) are configured to form a functional gap (G) towards the drive side in the coasting mode; and
- said functional gap (G) varies from 2.6 to 4.0 mm.

12. The multiplate clutch assembly (100) as claimed in any of the claims 4 and 6, wherein
- each of the friction plates (30A) has a plurality of friction petals (310) affixed equidistant from each other over its radial surface and a plurality of claws (315) on its outer periphery so as to get it fitted in the clutch housing (110);
- each of the clutch plates (30B) is configured to have a plurality of splines (30BT) on its inner peripheral surface so as to get it engaged with the splines of the moving hub (20);
- said splines (30BT) of the clutch plates (30B) are configured to get meshed with the splines provided on the extruded splined profile (20S) of the moving hub (20); and
- the claws (315) of the friction plates (30A) are engaged inside the respective slotted windows (115) of the housing clutch (110).

13. The multiplate clutch assembly (100) as claimed in claim 12, wherein
- the housing clutch assembly (10) comprises of a primary gear (105) and a clutch housing (110); the primary gear (105) is fitted at the back side of the clutch housing (110) with the help of suitable fastening means so as to make it an integrated housing clutch assembly (10);
- said primary gear (105) is configured to receive the torque from an output shaft of an engine and transfers the torque to the housing clutch (110) through a damping system positioned in the primary gear (105); and
- said housing clutch (110) is configured to have a plurality of slotted windows (115) for receiving the claws (315) of the friction plates (30A).

14. The multiplate clutch assembly (100) as claimed in claim 13, wherein
- the holder plate (60) has a plurality of holes (60H) on its periphery and the bolts (70) are configured to pass through these holes to get received and threaded there in the threaded groove (21BT) of the projection (21) of the moving hub (20); and
- said holder plate (60) is configured to compress the compression spring (50) in such a manner as to achieve the desired pressure on the plate stack (30) to transmit the torque from engine to the transmission of the vehicle.

Dated this 14th day of May 2024.

Sahastrarashmi Pund
Head – IPR
Endurance Technologies Ltd.

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