DESC:FIELD OF THE INVENTION

The invention relates to clutch assemblies and in particular, relates to a wet multi-plate clutch assembly for an automatic transmission system.

BACKGROUND

In the last few decades, a significant level of growth and development has been witnessed in the realm of automobiles. With the advancement in technology, automatic transmission systems are becoming a preferred type of transmission for different categories of vehicles, such as passenger vehicles, commercial vehicles, and earthmoving vehicles. Generally, an automatic transmission system includes planetary gear trains equipped with wet multi-plate clutches. In such an automatic transmission system, a wet multi-plate clutch includes an integrated cast iron piston which is positioned in the clutch housing and guided by piston guide pins.

However, the reliability and smooth operation of such wet multi-plate clutch depend on the precision of the manufacturing processes of the integrated cast iron piston. Such manufacturing processes are cumbersome and costly which further results in an increase of overall manufacturing cost of the wet multi-plate clutch. Also, the manufacturing and assembling of such wet multi-plate clutch require skilled manpower which is cost-intensive. Further, friction plates of the wet multi-plate clutch are provided with diamond groove patterns for oil flow. However, such groove patterns have less energy absorption capacity and lead to an increase in overall heat generation in the wet multi-plate clutch. Owing to the reduction in the overall clutch capacity, the vehicle performance is reduced during the operation of the automatic transmission system.

Therefore, there is a need for a solution that can address the above-mentioned issues.

SUMMARY

In an embodiment of the present disclosure, improved wet multi-plate clutch design system with isolated piston plate for planetary transmission is disclosed. The wet multi-plate clutch assembly includes a plurality of pressure plates and a plurality of friction plates. The plurality of friction plates is arranged consecutively between the plurality of pressure plates. Each of the plurality of friction plates is positioned at a predefined clearance from an adjacent pressure plate from among the plurality of pressure plates. Further, the wet multi-plate clutch assembly includes an isolated piston plate concentrically disposed with respect to the plurality of pressure plates and the plurality of friction plates. The isolated piston plate is adapted to exert pressure on the plurality of friction plates and the plurality of pressure plates. Further, the wet multi-plate clutch assembly includes an actuating member adapted to be hydraulically actuated to engage with the isolated piston plate. The actuating member engages with the isolated piston plate such that the isolated piston plate exerts pressure on the plurality of friction plates and the plurality of pressure plates to arrest a movement of at least one rotary element of a planetary gear set of the automatic transmission system.

To further clarify advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

Figure 1 illustrates a schematic view of a hydraulic system for operating a wet multi-plate clutch assembly disposed in an automatic transmission system, according to an embodiment of the present disclosure;

Figure 2 illustrates a partial sectional view of the automatic transmission system depicting the wet multi-plate clutch assembly, according to an embodiment of the present disclosure;

Figure 3 illustrates a front view of a friction plate of the wet multi-plate clutch assembly, according to an embodiment of the present disclosure; and

Figure 4 illustrates a graphical plot depicting modulating clutch pressure with respect to time duration, according to an embodiment of the present disclosure.

Further, skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have been necessarily been drawn to scale. For example, the flow charts illustrate the method in terms of the most prominent steps involved to help to improve understanding of aspects of the present invention. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.

DETAILED DESCRIPTION OF FIGURES

For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skilled in the art to which this invention belongs. The system, methods, and examples provided herein are illustrative only and not intended to be limiting.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
Figure 1 illustrates a schematic view of a hydraulic system 100 for operating a wet multi-plate clutch assembly 102 disposed in an automatic transmission system 104, according to an embodiment of the present disclosure. In an embodiment, the automatic transmission system 104 of a vehicle may include a plurality of wet multi-plate clutch assemblies, interchangeably referred to as the wet multi-plate clutch assemblies. The wet multi-plate clutch assembly 102 may be employed in the automatic transmission system 104 of a vehicle. In an embodiment, the vehicle may be embodied as one of passenger vehicles, commercial vehicles, earthmoving vehicles, and off-road vehicles, without departing from the scope of the present disclosure.

For the sake of brevity, single wet multi-plate clutch assembly 102 is depicted in Figure 1 and Figure 2 of the present disclosure. However, it should be appreciated by a person skilled in the art that it should not be construed as limiting, and the automatic transmission system 104 may include multiple wet multi-plate clutch assemblies, without departing from the scope of the present disclosure.

In an embodiment, the automatic transmission system 104 may include a plurality of planetary gear sets for transmitting power at different gear ratios from an engine to a drive system, such as wheels and tracks, for propelling the vehicle. The plurality of planetary gear sets may interchangeably be referred to as the planetary gear sets, without departing from the scope of the present disclosure. Further, the planetary gear sets may individually be referred to as the planetary gear set, without departing from the scope of the present disclosure.

The planetary gear set may include, but is not limited to a sun gear, a ring gear, at least one planet gear, and a planet carrier. In an embodiment, the sun gear, the ring gear, planet gear and the planet carrier may collectively and individually be referred to as the rotary elements and the rotary element, respectively, without departing from the scope of the present disclosure. The automatic transmission system 104 operates at different gear ratios which are attained by arresting movement of at least one rotary element of the planetary gear set of the automatic transmission system 104.

In the illustrated embodiment, the automatic transmission system 104 includes the wet multi-plate clutch assembly 102 employed for attaining different gear ratios in the automatic transmission system 104. In particular, the wet multi-plate clutch assembly 102 may be adapted to arresting movement of at least one rotary element in order to attain different gear ratios. The present disclosure is explained with respect to the wet multi-plate clutch assembly 102 and the planetary gear set.

However, it should be appreciated by a person skilled in the art that the present disclosure can equally be implemented with respect to other wet multi-plate clutch assembly 102 and planetary gear sets, without departing from the scope of the present disclosure. Constructional and operational details of the wet multi-plate clutch assembly are explained in subsequent sections of the present disclosure.

Figure 2 illustrates a partial sectional view of the automatic transmission system 104 depicting the wet multi-plate clutch assembly 102, according to an embodiment of the present disclosure. Referring to Figure 1 and Figure 2, the wet multi-plate clutch assembly 102 may be hydraulically operated to restrict the movement of at least one rotary element of the planetary gear set (as shown in Figure 2), such as the ring gear 202, the planet gears 204, and the sun gear (not shown). In an embodiment, the automatic transmission system 104 may include the hydraulic system 100 for operating the wet multi-plate clutch assembly 102.

Referring to Figure 1, in the illustrated embodiment, the hydraulic system 100 may include, but is not limited to, an oil sump 106, a suction strainer 108, a prime mover 110, a hydraulic pump 112, a filter assembly 114, a main relief valve 116, and a clutch control valve 118. The oil sump 106 may be adapted to store fluid, such as oil, to be transferred to the wet multi-plate clutch assembly 102. Further, the suction strainer 108 may be positioned downstream to the oil sump 106 and upstream to the hydraulic pump 112. The suction strainer 108 may be adapted to restrict particulate matter flowing in the oil towards the hydraulic pump 112.

The hydraulic pump 112 may be adapted to be driven through the prime mover 110. The hydraulic pump 112 may be adapted to draw the oil from the oil sump 106 and propel a flow of the oil to the wet multi-plate clutch assembly 102. Further, the main relief valve 116 may be adapted to be operated to control oil pressure and the flow of oil from the oil sump 106 through the hydraulic pump 112. In the illustrated embodiment, the main relief valve 116 may be provided with a drain port 120. The hydraulic system 100 also includes the filter assembly 114 positioned downstream to the hydraulic pump 112 and upstream to the clutch control valve 118. In an embodiment, the filter assembly 114 may be provided with a bypass valve.

Furthermore, each of the wet multi-plate clutch assembly 102 may be coupled to the clutch control valve 118. The clutch control valve 118 may be positioned upstream to the wet multi-plate clutch assembly 102. The clutch control valve 118 may be in communication with a controller configured to operate the clutch control valve 118. The controller may be configured to generate a signal 122 to operate the clutch control valve 118. Upon receiving the signal 122 from the controller, the clutch control valve 118 may allow the flow of oil to the wet multi-plate clutch assembly 102 through the clutch control valve 118. In the illustrated embodiment, the clutch control valve 118 may be provided with a drain port 124.

In an embodiment, the wet multi-plate clutch assembly 102 may be operable between an engaged position and a disengaged position. In the engaged position, the wet multi-plate clutch assembly 102 may be adapted to arrest the movement of the at least one rotary element of the planetary gear set. The wet multi-plate clutch assembly 102 may be operated to the engaged position when the clutch control valve 118 allows the flow of oil to the wet multi-plate clutch assembly 102. Further, the wet multi-plate clutch assembly 102 may be operated to the disengaged position when the clutch control valve 118 restricts the flow of oil to the wet multi-plate clutch assembly 102.

Referring to Figure 2, the wet multi-plate clutch assembly 102 may include, but is not limited to, clutch housing 102-1, a plurality of friction plates 206 and a plurality of pressure plates 208. The plurality of friction plates 206 may individually be referred to as a first friction plate 206-1, a second friction plate 206-2, a third friction plate 206-3, …., and nth friction plate 206-n. Further, the plurality of friction plates 206 may interchangeably be referred to as the friction plates, without departing from the scope of the present disclosure. Similarly, the plurality of pressure plates 208 may interchangeably be referred to as the pressure plates 208, without departing from the scope of the present disclosure. Further, the pressure plates 208 may individually be referred to as a first pressure plate 208-1, a second pressure plate 208-2, …., and the nth pressure plate 208-n.

Figure 3 illustrates a front view of the friction plate 206 of the wet multi-plate clutch assembly 102, according to an embodiment of the present disclosure. Referring to Figure 2 and Figure 3, in the illustrated embodiment, each of the friction plates 206 may include a pair of friction surfaces 210-1, 210-2. In an embodiment, the pair of friction surfaces 210-1, 210-2 may interchangeably be referred to as the friction surfaces 210, without departing from the scope of the present disclosure. Each of the friction surfaces 210 may be provided with a plurality of circular grooves 212 adapted to retain lubricant on the friction surfaces 210. Further, each of the friction surfaces 210 may be provided with a plurality of inclined grooves 214 combined with the plurality of circular grooves 212 adapted to define a flow path for a flow of lubricant. In the illustrated embodiment, the plurality of inclined grooves 214 may include a first set of inclined grooves 214-1 and a second set of inclined grooves 214-2. In an embodiment, the plurality of inclined grooves 214 may interchangeably be referred to as the lubricant grooves 214, without departing from the scope of the present disclosure.

In an embodiment, each of the friction plates 206 may be embodied as one of a paper based friction plate, elastomer based friction plate, and graphite based friction plate. The friction plates 206 may be arranged consecutively between the pressure plates 208. In the illustrated embodiment, the first friction plate 206-1 may be positioned between an end housing 215 of the automatic transmission system 104 and the first pressure plate 208-1. Similarly, the second friction plate 206-2 may be positioned between the first pressure plate 208-1 and the second pressure plate 208-2. Further, the third friction plate 206-3 may be positioned consecutively to the second pressure plate 208-2.

Each of the friction plates 206 may be positioned at a predefined clearance ß from an adjacent separator plate from among the pressure plates 208. For instance, the first friction plate 206-1 may be positioned at the predefined clearance ß from the first pressure plate 208-1. Further, the second friction plate 206-2 may be positioned at the predefined clearance ß from each of the first pressure plate 208-1 and the second pressure plate 208-2.

Similarly, the third friction plate 206-3 may be positioned at the predefined clearance ß from the second pressure plate 208-2. Owing to such predefined clearance ß between the friction plate 206 and the adjacent pressure plates 208, viscous drag torque is substantially reduced during the relative movement of the friction plate 206 and the adjacent pressure plates 208, which is explained later in the present disclosure. In an embodiment, the predefined clearance ß may be in a range of 0.45 mm to 0.65 mm.

Further, the wet multi-plate clutch assembly 102 may include an isolated piston plate 216 concentrically disposed with respect to the plurality of friction plates 206 and the plurality of pressure plates 208. In the illustrated embodiment, the isolated piston plate 216 may be disposed adjacent to the third friction plate 206-3. The isolated piston plate 216 may be positioned at the predefined clearance ß from the third friction plate 206-3. The isolated piston plate 216 may be adapted to exert pressure on the plurality of friction plates 206 and the plurality of pressure plates 208.

Referring to Figure 2, the wet multi-plate clutch assembly 102 may include an actuating member 218. The actuating member 218 may be adapted to be engaged with the isolated piston plate 216. In particular, the actuating member 218 may be adapted to be hydraulically actuated to engage with the isolated piston plate 216. The actuating member 218 engages with the isolated piston plate 216 such that the isolated piston plate 216 exerts pressure on the plurality of friction plates 206 and the plurality of pressure plates 208 to arrest the movement of the at least one rotary element of the planetary gear set.

In the illustrated embodiment, the actuating member 218 may be embodied as a piston, without departing from the scope of the present disclosure. The actuating member 218 may be in fluid communication with the hydraulic system 100. In particular, the actuating member 218 may be adapted to be coupled to the hydraulic system 100 configured to supply the flow of fluid to the actuating member. The actuating member 218 may be in fluid communication with the clutch control valve 118 of the hydraulic system 100.

The actuating member 218 may be adapted to be moved towards the isolated piston plate 216 when the flow of fluid is supplied to the actuating member 218 from the hydraulic system 100. The actuating member 218 may be adapted to apply pressure on the isolated piston plate 216 in a direction towards the pressure plates 208 and the friction plates 206. In particular, when the actuating member 218 applies pressure on the isolated piston plate 216, each of the friction plates 206 engages with the adjacent pressure plates 208.

Further, the actuating member 218 may be adapted to be moved away from the isolated piston plate 216, when the flow of fluid may be halted to the actuating member 218 from the hydraulic system 100. In particular, the actuating member 218 may return back to an initial position, when the flow of fluid may be halted to the actuating member 218 from the clutch control valve 118 of the hydraulic system 100. Subsequently, the actuating member 218 may release pressure on the isolated piston plate 216 in a direction away from the friction plates 206 and the pressure plates 208. In particular, when the actuating member 218 releases pressure on the isolated piston plate 216, each of the friction plates 206 disengages from the adjacent pressure plates 208.

Referring to Figure 2, the wet multi-plate clutch assembly 102 may also include a plurality of resilient members 220. In an embodiment, the plurality of resilient members 220 may interchangeably be referred to as the resilient members 220, without departing from the scope of the present disclosure. Each of the resilient members 220 may be embodied as a helical coil spring. Each of the resilient members 220 may be positioned such that a threshold pressure associated with the engagement of the wet multi-plate clutch assembly 102 is optimised. Further, the wet multi-plate clutch assembly 102 may include a piston seal 224 and a housing seal 226. The piston seal and the housing seal may be provided to eliminate leakage of the lubricant to other regions in the automatic transmission system. Furthermore, the wet multi-plate clutch assembly 102 may be provided with a guided pin 228 connected to the end housing 215 and the clutch housing 102-1.

During operation of the wet multi-plate clutch assembly 102, the lubricant may be trapped between stationary plates, i.e., the pressure plates 208, and rotating plates, i.e., the friction plates 206, of the wet multi-plate clutch assembly 102. A velocity gradient (dv/dx) may be developed across the lubricant between the pressure plate 208 and the friction plate 206. Such a velocity gradient, in turn, generates shear stress in the lubricant having a magnitude which is dependent on various factors. Such factors may include, but is not limited to, a force applied to the plates, i.e., the friction plates 206 and the pressure plates 208, a viscosity of the lubricant, and a separation distance, i.e., the predefined clearance ß, between the friction plate 206 and the pressure plate 208. The lubricant may be adapted to absorb heat energy generated from the wet multi-plate clutch assembly 102 during engagement operation and conducts it away from the torque generating interfaces.

During the engagement operation of the wet multi-plate clutch assembly 102, the controller may transmit the signal to the clutch control valve 118. Subsequently, based on the received signal, the clutch control valve 118 may allow the flow of fluid to the wet multi-plate clutch assembly 102. As explained earlier, the actuating member 218 of the wet multi-plate clutch assembly 102 may be in fluid communication with the clutch control valve 118 of the hydraulic system 100. The clutch control valve 118 may supply the flow of fluid to the actuating member 218. Upon receiving the flow of fluid from the clutch control valve 118, the actuating member 218 may apply pressure on the isolated piston plate 216 in a direction towards the friction plates 206 and the pressure plates 208.

Subsequently, the isolated piston plate 216 may push the friction plates 206 and the pressure plates 208. Owing to the relative movement between the each of the friction plates 206 and the adjacent pressure plates 208, the lubricant may flow through the lubricant grooves 214 on friction plate 206 and the adjacent pressure plate 208. Further, the lubricants flowing through the lubricant grooves 214 provide higher energy absorption and avoid temperature rise during clutch engagement.

During disengagement operation of the wet multi-plate clutch assembly 102, the clutch control valve 118 may restrict the flow of fluid to the wet multi-plate clutch assembly 102. Subsequently, the actuating member 218 may release pressure on the isolated piston plate 216 of the wet multi-plate clutch assembly 102. Further, the isolated piston plate 216 may move in the direction away from the friction plates 206 and the pressure plates 208. Owing to such movement of the isolated piston plate 216, each of the friction plates 206 may disengage from the adjacent pressure plates 208. Owing to that predefined clearance ß is ensured with the help of resilient members and also the viscous drag torque is substantially reduced during disengagement of the wet multi-plate clutch assembly 102.

Figure 4 illustrates a graphical plot 400 depicting modulated clutch pressure with respect to time duration, according to an embodiment of the present disclosure. Referring to Figure 4, a first curve 402 indicates variation in clutch pressure with respect to time duration during the disengagement operation of the wet multi-plate clutch assembly 102. Further, a second curve 404 indicates variable clutch pressure with respect to time duration during the engagement operation of the wet multi-plate clutch assembly 102. Referring to the second curve 404, it can be clearly inferred that an optimum threshold clutch pressure (1~1.5 bar) 406 is attained owing to the implementation of the improved wet multi-plate clutch assembly 102. In particular, the optimum threshold clutch pressure 406 is ensured and further clutch modulation with clutch holding phase incorporated such that the overall stability of the wet multi-plate clutch assembly 102 is substantially increased.

As would be gathered, the present disclosure relates to the wet multi-plate clutch assembly 102 for the automatic transmission 104. As mentioned earlier, the wet multi-plate clutch assembly 102 can be employed in the automatic transmission system 104 of the vehicle, such as passenger vehicles, commercial vehicles, earthmoving vehicles, and off-road vehicles. Therefore, the wet multi-plate clutch assembly 102 has a wide range of applications.

As explained earlier, the wet multi-plate clutch assembly 102 includes the actuating member 218 and the isolated piston plate 216. The actuating member 218 moves relative to the isolated piston plate 216 such that the actuating member 218 may push the isolated piston plate 216 to engage the wet multi-plate clutch assembly 102. Owing to such construction and arrangement of the actuating member 218 and the isolated piston plate 216, overall manufacturing cost and complexity associated with the manufacturing of the wet multi-plate clutch assembly 102 is substantially reduced. Also, owing to such arrangement and construction, the wet multi-plate clutch assembly 102 can be assembled without requiring skilled manpower.

Further, each of the friction plates 206 includes the plurality of inclined grooves 214 and the plurality of circular grooves 212. The plurality of circular grooves 212 is able to retain a higher amount of lubricant on the friction surfaces 210 of the friction plate 206. Further, the plurality of circular grooves 212 is able to define a flow path for the flow of lubricant. Owing to such grooves on the friction surfaces 210, the friction plate 206 can absorb a higher amount of energy during the operation of the wet multi-plate clutch assembly 102. In particular, the plurality of inclined grooves 214 combined with the plurality of circular grooves 212 may be able to absorb a higher amount of energy during the operation. Further, the wet multi-plate clutch assembly 102 is able to achieve higher heat transfer due to radiation and convection. Furthermore, the wet multi-plate clutch assembly 102 is positioned in the automatic transmission 104 such that contaminates, such as dust or dirt, may not come in contact with the wet multi-plate clutch assembly 102. Therefore, the overall service life of the wet multi-plate clutch assembly 102 is substantially increased.

Further, the grooves, i.e., the inclined grooves 214 and the circular grooves 212, ensures an additional flow of lubricant for a faster cooling rate of the friction plate 206 and the pressure plate 208. In addition, the grooves ensure fast oil film cutting-off without any delay time, and thereby enhance clutch responsiveness and smoother clutch engagement. Therefore, overall viscous drag torque is also substantially reduced during the operation of the wet multi-plate clutch assembly 102. Also, owing to the optimum threshold clutch pressure and the predefined clearance ß between the friction plate 206 and the adjacent pressure plate 208, overall viscous drag torques are substantially reduced in a disengaged condition of the wet multi-plate clutch assembly 102. Therefore, the present disclosure offers the wet multi-plate clutch assembly 102 that is efficient, economical, compact, flexible, and effective for the automatic transmission system.

While specific language has been used to describe the present subject matter, any limitations arising on account thereto, are not intended. As would be apparent to a person in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein. The drawings and the foregoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment.
,CLAIMS:1. A wet multi-plate clutch assembly for an automatic transmission system, the wet multi-plate clutch assembly comprising:
a plurality of pressure plates;
a plurality of friction plates arranged consecutively between the plurality of pressure plates, wherein each of the plurality of friction plates is positioned at a predefined clearance from an adjacent pressure plate from among the plurality of pressure plates;
an isolated piston plate concentrically disposed with respect to the plurality of pressure plates and the plurality of friction plates, wherein the isolated piston plate is adapted to exert pressure on the plurality of friction plates and the plurality of pressure plates; and
an actuating member adapted to be hydraulically actuated to engage with the isolated piston plate, wherein the actuating member engages with the isolated piston plate such that the isolated piston plate exerts pressure on the plurality of friction plates and the plurality of pressure plates to arrest a movement of at least one rotary element of a planetary gear set of the automatic transmission system.

2. The wet multi-plate clutch assembly as claimed in claim 1, wherein each of the plurality of friction plates is one of a paper based friction plate, an elastomer based friction plate, and a graphite based friction plate.

3. The wet multi-plate clutch assembly as claimed in claim 1, wherein each of the plurality of friction plates includes a pair of friction surfaces, each of the pair of friction surfaces is provided with a plurality of circular grooves adapted to retain lubricant and displacement on the pair of friction surfaces.

4. The wet multi-plate clutch assembly as claimed in claim 3, wherein each of the pair of friction surfaces is provided with a plurality of inclined grooves combined with the plurality of circular grooves adapted to define a flow path for a flow of lubricant.

5. The wet multi-plate clutch assembly as claimed in claim 1, wherein the actuating member is adapted to be coupled to a hydraulic system configured to supply a flow of fluid to the actuating member.

6. The wet multi-plate clutch assembly as claimed in claim 5, wherein the actuating member is adapted to be moved towards the isolated piston plate when the flow of fluid is supplied to the actuating member from the hydraulic system.

7. The wet multi-plate clutch assembly as claimed in claim 6, wherein the actuating member is adapted to apply pressure on the isolated piston plate in a direction towards the plurality of pressure plates and the plurality of friction plates, wherein each of the plurality of friction plates engages with the adjacent pressure plate.

8. The wet multi-plate clutch assembly as claimed in claim 5, wherein the actuating member is adapted to be moved away from the pressure plate when the flow of fluid is halted to the actuating member from the hydraulic system.

9. The wet multi-plate clutch assembly as claimed in claim 8, wherein the actuating member is adapted to release pressure on the isolated piston plate in a direction away from the plurality of pressure plates and the plurality of friction plates, wherein the each of plurality of friction plates disengages from the adjacent pressure plate.

10. The wet multi-plate clutch assembly as claimed in claim 1, wherein the predefined clearance is in a range of 0.45 mm to 0.65 mm.