In particular, this disclosure relates to an engine component. More specifically, it relates to a rocker arm assembly of an internal combustion engine.
DEFINITIONS
As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used indicates otherwise.
BORE: The term "BORE" hereinafter refers to a hole or a shape defining a space shaped like a cylinder typically made by using a boring tool.
The above definition is in addition to that expressed in the art. BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Generally, an internal combustion engine has a set of rocker arms to actuate the intake and the exhaust valves. There are separate rocker arms for each valve. The rocker arm is mounted on a rocker shaft. A push rod is configured to cause the rocker arms to rotate or pivot, to thereby actuate the valves. The push rod extends through the engine to connect a camshaft. As the camshaft rotates, the push rod moves the rocker arms to open and close the valves. The camshaft is designed to open and close the valves in conjunction with the cycling of the piston in the cylinder. The rocker arm requires sufficient lubrication for its efficient operation. The lubrication helps the rocker arm in reducing the friction between the mating members, the components wear and minimizing the noise.
The conventional rocker arm uses a bush which is either made of a brass or a copper metal. These bushes are used in between the interface between the rocker arm and its mating rocker shaft to minimize the friction. But, due to the specific

material requirements for the bush, the cost of rocker arm assembly increases which in-turn increases the overall cost of the engine.
US patent no. 5553583 awarded as "Rocker arm lubrication arrangement" describes a rocker arm lubrication arrangement for an engine. The rocker arm comprises a rocker arm body having a central bore into which a bush bearing locates and through which the support shaft locates for supporting the rocker arm for pivotal movement thereabout. The shaft has a longitudinally extending lubricant supply bore and radially upwardly extending supply bores. The Lubricant passes along the longitudinally extending supply bore to the radially extending bores and then exits via corresponding bores in the rocker arms.
US patent no. 8915224 awarded as "Rocker shaft shim" describes a shim for use in mounting a rocker shaft to a rocker shaft mount. The shim consist of a body having a first surface portion adapted to contact a rocker shaft in use and a second surface portion adapted to contact a rocker shaft mount in use. The shims are composed of a copper alloy, preferably bronze.
US patent no. 5970932 awarded as "Rocker arm assembly" describes an assembly comprising a rocker arm having a solid cylindrical section, a pushrod lever extending perpendicular to a longitudinal axis of the solid cylindrical section, a valve lever, a bushing matingly fitted around the solid cylindrical section, and a pair of guides fitting over the bushing. The bushing is made of an oil impregnated bronze and the pair of guides are made of aluminum.
Based on the study of the above prior-art assembly, it is observed that most of the assembly uses the bush or similar element between the interface of the rocker shaft and the rocker arm. From the study of the prior art, it is also noted that the bushes are made of a copper or similar alloying elements which generally increase the cost of the rocker arm assembly and the overall cost of the engine.
Therefore, there is a need for a rocker arm assembly that eliminates the aforementioned shortcomings.

OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to provide a rocker arm assembly.
Another object of the present disclosure is to provide a rocker arm assembly having oil film lubrication.
Yet another object of the present disclosure is to provide a rocker arm assembly which can minimize the friction between mating members.
Still another object of the present disclosure is to provide a rocker arm assembly which reduces the cost of an IC engine.
Yet another object of the present disclosure is to provide a rocker arm assembly which prevents the leakage of the lubricating fluid.
Still another object of the present disclosure is to provide a rocker arm assembly which reduces the overall weight of the engine.
Yet another object of the present disclosure is to provide a rocker arm assembly which reduces the wear of components.
Still another object of the present disclosure is to provide a rocker arm assembly which minimizes the noise between mating surfaces of the assembly.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure envisages a rocker arm assembly. The rocker arm assembly comprises a rocker arm, a bore configured on the rocker arm defining a passage, a helical groove engraved on the passage, a rocker shaft configured to be

inserted in the passage having an axial hole configured thereon for receiving pressurized lubricant and a circumferential groove configured on the rocker shaft. The groove is configured to be in contact with the helical groove to form a fluid pocket therebetween. The fluid pocket facilitates the lubrication between the passage and the rocker shaft.
Further, a vertically extending radial hole is provided on an operative end portion of the rocker shaft. The radial hole is substantially perpendicular to the axial hole of the rocker shaft and configured to facilitate the fluid communication between the axial hole and the circumferential groove.
The assembly enables the lubricant to flow from the axial hole to the circumferential groove to lubricate a mating space formed between the inner wall surface of the passage and the operative end portion of the rocker shaft.
In a preferred embodiment, the diameter of the radial hole is smaller than the diameter of the axial hole provided on the rocker shaft.
In an embodiment the helical groove has a pitch of 12.9 mm to 13.1 mm and has a recess of 0.4 mm to 0.6 mm.
In another embodiment, the ratio of the depth of the helical groove to the diameter of said bore is in the range of 0.025 to 0.05.
In an embodiment, the thickness of the fluid pocket formed at the point of contact of the circumferential groove with the helical groove is in the range of 1.0 mm to 2.0 mm.
In an embodiment, the clearance between the operative end portion of the rocker shaft and the inner wall surface of the bore is in the range of 0.5 mm to 0.9 mm.
In an embodiment, the rocker shaft and the rocker arm is made of forged steel.
In another embodiment, the rocker shaft and the rocker arm is made of carbon steel.

Further, the present disclosure also discloses an internal combustion engine comprising a cylinder head, a camshaft, a valve train is connected to the crankshaft, a rocker arm assembly, a rocker lever screw and an engine valve.
In an embodiment, a first end of the rocker arm being in communication with the engine valve and a second end of the rocker arm configured to engage the rocker lever screw. The rocker arm is being oscillated by the engine valve.
In an embodiment, lubricant flowing through the rocker arm and the mating space is engine oil.
Advantageously, it avoids the requirement of the bush as the interface between the rocker arm and the rocker shaft are being lubricated by means of the suitable lubricant. Therefore, it does not require the bush assembly in between the mating space. And thereby, the friction, the wear of the component and the noise are easily reduced and eliminated.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
The rocker arm assembly, of the present disclosure, will now be described with the help of the accompanying drawing, in which:
Figure 1(a) shows an isometric view of assembly of the conventional rocker arm with a rocker shaft;
Figure 1(b) shows an exploded view of the conventional rocker arm assembly;
Figure 2 shows an isometric view of a conventional rocker arm having a bush arranged in a central bore of the rocker arm;
Figure 3 shows an exploded view of the rocker shaft with the rocker arm, in accordance with an embodiment of the present disclosure;
Figure 4(a) shows an isometric top view of the rocker arm, in accordance with an embodiment of the present disclosure;

Figure 4(b) shows an isometric side view of the rocker arm indicating a passage and a channel for the lubricant, in accordance with an embodiment of the present disclosure;
Figure 5 shows a perspective view of the rocker arm indicating a helical groove on a bore along with a first passage and a channel, in accordance with an embodiment of the present disclosure;
Figure 6 shows a perspective view of a rocker shaft with a circumferential groove bore, in accordance with an embodiment of the present disclosure;
Figure 7(a) and 7(b) shows a perspective view of a fluid pocket formed by the intersection of a helical groove and a circumferential groove, in accordance with an embodiment of the present disclosure; and
Figure 8 shows a sectional view of a rocker arm assembled on a rocker shaft for oil gallery demonstration and an engine valve in contact rocker lever screw, in accordance with an embodiment of the present disclosure.
LIST OF REFERENCE NUMERALS
10 - Rocker assembly
10' - Rocker assembly (prior art)
12 - Rocker arm
12' - Rocker arm (prior art)
14 - Axial hole
16 - Fluid pocket
18 - Bore
20 - Helical groove

22 -

Circumferential groove

24 - Channel
24' - Channel (prior art)
26 - First passage
28 - Rocker shaft
28a - Rivet
28' - Rocker shaft (prior art)
30 - Radial hole
32 - Engine valve
34 - Rocker lever screw
36 - Bush (prior art)
38 - Rocker support (prior art)
40 - Second passage
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments,

well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a", "an", and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises", "comprising", "including", and "having", are open ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
When an element is referred to as being "mounted on", "engaged to", "connected to", or "coupled to" another element, it may be directly on, engaged, connected or coupled to the other element. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed elements.
The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region or section from another component, region, or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.
Terms such as "inner", "outer", "beneath", "below", "lower", "above", "upper", and the like, may be used in the present disclosure to describe relationships between different elements as depicted from the figures.

Typically, an internal combustion engines have a set of rocker arms for actuating the intake and the exhaust valves. The rocker arm is mounted on a rocker shaft as shown in Figure 1(a), Figure 1(b) and Figure 2. A push rod is configured to cause the rocker arms to rotate or pivot to actuate the valves. The push rod extends through the engine to connect a camshaft. As the camshaft rotates, the push rod moves the rocker arms to open and close the valves.
Further, the rocker arm requires sufficient lubrication for its efficient operation. The lubrication helps the rocker arms in reducing the friction between the mating members, reducing the wear of the components as well as in minimizing the noise.
To overcome the aforementioned drawbacks, a conventional rocker arm assembly 10' uses a bush 36 which is either made of a brass or a copper metal or an alloy of copper as shown in Figure 1(b). The bush 36 is used in between the interface between the rocker arm 12' and its mating rocker shaft 28' to minimize the friction. However, the conventional bush 36 is made of metal materials like copper, brass and therefore, the cost of rocker arm assembly 10' increases, which in-turn increases the overall cost of the engine.
Moreover, due to the presence of a set of rocker arms with the engine, the same number of bush is required, which in-turn increases the overall weight as well as overall cost of the engine.
Therefore, the present disclosure envisages a rocker arm assembly 10, particularly for an internal combustion engine of a vehicle that overcomes the aforementioned drawbacks. The lubrication of the rocker assembly 10 is a thin oil-film based lubrication and thus, comprises a rocker arm 12 and a rocker shaft 28.
The rocker arm assembly 10 (hereinafter referred to as "assembly 10") will now be described with reference to Figure 3, Figure 4(a) and Figure 4(b).
The rocker arm assembly 10 comprises the rocker arm 12 having a bore 18 configured thereon, a helical groove 20 configured on an inner wall surface of the

bore 18, the rocker shaft 28, and a circumferential groove 22 as shown in the Figure 3.
The rocker shaft 28 has an operative end portion which is to be received in the bore 18. Figure 5 shows a perspective view of the rocker arm 12 indicating the helical groove 20 on the bore 18 in accordance with an embodiment of the present disclosure. The helical groove 20 is formed by means of a lathe machine.
The rocker shaft 28 is provided with an axial hole 14 with both ends blind, thereon for receiving a lubricating fluid. The lubricating fluid is received from a second passage 40 configured on the surface of the rocker shaft 28. Figure 6 shows a perspective view of a rocker shaft with a circumferential groove bore and a second passage for receiving the lubricant in accordance with an embodiment of the present disclosure.
The circumferential groove 22 is being provided on the operative end portion of the rocker shaft 28 as shown in the Figure 3 and Figure 6. The groove 22 is configured to be in contact with the helical groove 20 to form a fluid pocket 16 therebetween as shown in Figure 7(a) and 7(b). The fluid pocket thus formed lubricates the operative end portion of the rocker shaft 28 and the operative inner wall surface of the bore 18.
Further, the rocker shaft 28 is provided with a vertical extending radial hole 30 on the operative end portion of the rocker shaft 28 as shown in the Figure 6. The radial hole 30 is substantially perpendicular to the axial hole 14 of the rocker shaft 28 to facilitate the communication of the lubricating fluid. Also, the radial hole 30 is configured to facilitate the fluid communication between the axial hole 14 and the circumferential groove 22.
In an embodiment, the radial hole 30 has a narrower diameter with respect to the diameter of the axial hole 14 configured on the rocker shaft 28.

Further, the lubricating fluid flows through at least one point of contact from the operative end portion of the rocker shaft 28 towards the inner wall surface of the bore 18.
In an embodiment, the helical groove 20 has a pitch of 12.9 mm to 13.1 mm and has a depth of groove is in the range of0.4 mm to 0.6 mm
In a preferred embodiment, the helical groove 20 having the pitch of 13.0 mm and having the recess of 0.5 mm.
In a preferred embodiment, the helical groove 20 is having the depth of 0.5mm.
In an embodiment, the ratio of the depth of the helical groove 20 to the diameter of the bore 18 is in the range of 0.025 to 0.05.
In another embodiment, the ratio of the depth of the circumferential groove 22 to the diameter of said rocker shaft 28 is in the range of 0.025 to 0.05.
In an embodiment, the thickness of the fluid pocket 16 formed at the point of contact of the circumferential groove 22 with the helical groove 20 is in the range of 1.0 mm to 2.0 mm.
The axial hole 14 provided on the rocker shaft 28 is configured to carry the pressurized lubricant, and thereby enabling the distribution of lubricant across the circumferential groove 22. The axial hole 14 is located at the substantial center of the rocker shaft 28.
In an embodiment, the pressure of lubricant flowing through the axial hole 14 of the rocker shaft 28 is in the range of 0.5 bar to 2.0 bar.
In a preferred embodiment, the pressure of lubricant flowing through the axial hole 14 is 0.5 bar.
The rocker arm 12 is provided with a first passage 26 on an operative top surface of the rocker arm 12. The first passage 26 is configured to be in fluid communication with the rocker shaft 28. Also, the operative top surface of the

rocker arm 12 is provided with a flow channel 24, which is configured to be in communication with the first passage 26. The first passage 26 and the flow channel 24 are shown in the Figure 4(b) and Figure 8 in accordance with the present disclosure. Figure 18 a sectional view of the rocker arm 12 assembled on the rocker shaft 28 for oil gallery demonstration and the engine valve 32 in contact with the rocker lever screw 34.
The rocker arm 12 and the rocker shaft 28 are made of same material. Also, the hardness of the inner wall surface of the bore 18 and the hardness of the rocker shaft 28 are made equal, so as to minimize the wear between mating component .i.e., the operative end portion of the rocker shaft 28 and the inner wall surface of the bore 18.
In an embodiment the rocker arm 12 and the rocker shaft 28 are made of forged steel.
In another embodiment, the rocker arm 12 and the rocker shaft 28 are made of carbon steel.
In an embodiment, the clearance between the operative end portion of the rocker shaft 28 and the inner wall surface of the bore 18 is in the range of 0.5 mm to 0.95 mm.
In a preferred embodiment, the clearance between the operative end portion of the rocker shaft 28 and the inner wall surface of the bore 18 is 0.9 mm.
Further, the present disclosure also discloses the internal combustion engine comprising a cylinder head, a camshaft, a valve train connected to the crankshaft, a rocker arm assembly 10, a rocker lever screw 34 and a engine valve 32 as shown in the Figure 8.
A first end of the rocker arm 12 being in communication with the engine valve 32 and a second end of the rocker arm 12 configured to engage the rocker lever screw 34. The rocker arm 12 is being oscillated by the engine valve 32, to thereby actuate the rocker lever screw 34.

In an embodiment, the lubricant flowing through the rocker arm 12 and the mating space formed between the operative end portion of the rocker shaft 28 and the inner wall surface of the bore 18 is engine oil.
Advantageously, the assembly 10 eliminates the requirement of the bush as the interface between the rocker arm and the rocker shaft is being lubricated by means of the suitable lubricant. Further, the assembly 10 eliminates the friction between the components and reduces the wear of the components and reduces the noise generated due to friction as compared to the conventional assembly 10'.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a rocker arm assembly, that:
provides thin oil film lubrication between the interface of the matingly engaged rocker shaft and the inner wall surface of the rocker arm, and thereby it eliminates the requirements of the bush;
utilizes oil based lubrication system between the mating space and thereby it minimizes the friction between the mating surfaces;
reduces the wear between the mating component as the rocker shaft and the rocker arm are made of same type of steel as well as the mating surface is having similar hardness;

reduces the cost of the internal combustion engine as there is no requirement of the bush with the rocker arm assembly;
prevents the leakage of the lubricating fluid as the fluid pocket formed at the point of contact of the helical groove and the circumferential groove is perfectly locked;
reduces the overall weight of the engine as the rocker arm assembly eliminates the requirement of the bush; and
minimizes the noise between the mating components due to the presence of the oil film based lubrication system.
The foregoing description of the specific embodiments so fully reveals 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.
Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

The use of the expression "at least" or "at least one" suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

CLAIM:

1. A rocker arm assembly (10) comprising:
• a rocker arm (12);
• a bore (18) configured on said rocker arm (12) defining a passage ;
• a helical groove (20) provided on said bore (18);
• a rocker shaft (28) configured to be inserted in said passage, said shaft (28) having an axial hole (14) configured thereon for receiving lubricant; and
• a circumferential groove (22) configured on said rocker shaft (28),
said groove (22) configured to be in contact with said helical groove (20) to form a fluid pocket (16) therebetween for facilitating lubrication between said passage (22) and said rocker shaft (28).
2. The assembly (10) as claimed in claim 1, wherein a vertically extending radial hole (30) is configured on an operative end portion of said rocker shaft (28).
3. The assembly (10) as claimed in claim 2, wherein said radial hole (30) is substantially perpendicular to said axial hole (14) of said rocker shaft (28) to facilitate communication of lubricant.
4. The assembly (10) as claimed in claim 2, wherein said radial hole (30) is configured to facilitate fluid communication between said axial hole (14) and said circumferential groove (22).
5. The assembly (10) as claimed in claim 2, wherein the diameter of said radial hole (30) is smaller than the diameter of said axial hole (14).

6. The assembly (10) as claimed in claim 1, wherein said helical groove (20) is engraved on an inner wall surface of said bore (18).
7. The assembly as (10) claimed in claim 1, wherein said helical groove (20) is formed by means of a lathe machine.
8. The assembly (10) as claimed in claim 1, wherein said operative end portion of said rocker shaft (28) is configured to be received in said passage of said bore (18).
9. The assembly (10) as claimed in claim 1, wherein said circumferential groove (22) is configured on said operative end portion of said rocker shaft (28).
10. The assembly (10) as claimed in claim 1, wherein said assembly enables the lubricant to flow through at least one point of contact from said operative end portion of said rocker shaft (28) towards said inner wall surface of said bore (18).
11. The assembly (10) as claimed in claim 1, wherein said assembly enables the lubricant to flow from said axial hole (14) to said circumferential groove (22) to lubricate a mating space formed between said inner wall surface of said bore (18) and said operative end portion of said rocker shaft (28).
12. The assembly (10) as claimed in claim 1, wherein said helical groove (20) has a pitch of 12.9 mm to 13.1 mm.
13. The assembly (10) as claimed in claim 1, wherein said helical groove (20) has a recess of 0.4mm to 0.6 mm.
14. The assembly (10) as claimed in claim 1, wherein said helical groove (20) has a depth of 0.4 mm to 0.6 mm.

15. The assembly (10) as claimed in claim 1, wherein the ratio of the depth of said helical groove (20) to the diameter of said bore (18) is in the range of 0.025 to 0.05.
The assembly (10) as claimed in claim 1, wherein the ratio of the depth of said circumferential groove (22) to the diameter of said rocker shaft (28) is in the range of 0.025 to 0.05.
The assembly (10) as claimed in claim 1, wherein the thickness of said fluid pocket (16) formed at the point of contact of said circumferential groove (22) with said helical groove (20) is in the range of 1.0 mm to 2.0 mm.
18. The assembly (10) as claimed in claim 1, wherein a first passage (26) is provided on an operative top surface of said rocker arm (12), said first passage (26) configured to be in fluid communication with said rocker shaft (28).
19. The assembly (10) as claimed in claim 1, wherein a flow channel (24) provided on an operative top surface of said rocker arm (12), said channel (24) configured to be in communication with said first passage (26).
20. The assembly (10) as claimed in claim 1, wherein said axial hole (14) is configured to carry pressurized lubricant, thereby enabling the distribution of lubricant across said circumferential groove (22) and over said inner wall surface of said bore (18).
21. The assembly (10) as claimed in claim 1, wherein pressure of lubricant flowing through said axial hole (14) is in the range of 0.5 bar to 2.0 bar.
22. The assembly (10) as claimed in claim 1, wherein said rocker arm (12) and said rocker shaft (28) are made of forged steel.
23. The assembly (10) as claimed in claim 1, wherein said rocker arm (12) and said rocker shaft (28) are made of carbon steel.

24. The assembly (10) as claimed in claim 1, wherein the clearance between the operative end portion of said rocker shaft (28) and said inner wall surface of said bore (18) is in the range of 0.5 mm to 0.9 mm.
25. The assembly (10) as claimed in claim 1, wherein said axial hole (14) is located at the substantial centre of said rocker shaft (28).
26. The assembly (10) as claimed in claim 1, wherein lubricant is engine oil.
27. An internal combustion engine comprising:

• a cylinder head
• a camshaft;
• a valve train connected to said crankshaft,
• a rocker arm assembly (10) comprising:
o a rocker arm (12);
o a bore (18) configured on said rocker arm (12) defining a passage;
o a helical groove (20) provided on said passage;
o a rocker shaft (28) configured to be inserted in said passage having an axial hole (14) configured thereon for receiving pressurized lubricant; and
o a circumferential groove (22) configured on said rocker shaft (28),
• a rocker lever screw (34); and
• an engine valve (32).

28. The engine as claimed in claim 27, wherein a first end of said rocker arm (12) being in communication with said engine valve (32) and a second end of said rocker arm (12) configured to engage said rocker lever screw (34), said rocker arm (12) being oscillated by said engine valve (32).
29. A vehicle having an internal combustion engine comprising a rocker arm assembly (10) as claimed in any one of the preceding claims 1-28.