CLIAMS:We Claim:
1. An engine lubrication system 12 comprising:
a first fluid supply passage 14 provided on a cylinder head 16 for communicating fluid from an oil sump 18;
a camshaft bearing cap 20 provided on the cylinder head 16, a cavity portion 22 defined on the camshaft bearing cap 20, the first fluid supply passage 14 being connected to the cavity portion 22 of the camshaft bearing cap 20;
a second fluid passage 26 fluidically connected to the cavity portion 22 of the camshaft bearing cap 20; and
a third fluid passage 28 defined within the cylinder head 16 and fluidically connected to the cavity portion 22 of the camshaft bearing cap 20.

2. The engine lubrication system 12 as claimed in claim 1, wherein the second fluid passage 26 is for an oil control valve.

3. The engine lubrication system 12 as claimed in claim 1, wherein the third fluid passage 28 is a set of hydraulic lash adjuster galleries.

4 The engine lubrication system 12 as claimed in claim 1, wherein the camshaft bearing cap 20 includes a bottom bearing cap 24 adapted to be connected on the cylinder head 16, and a top bearing cap 27 adapted to be connected to the bottom bearing cap 24.

5. The engine lubrication system 12 as claimed in claim 4, wherein the cavity portion 22 is defined on the bottom bearing cap 24.

6. The engine lubrication system 12 as claimed in claim 5, wherein the cavity portion 22 is adapted to get sealed when the bottom bearing cap 24 is engaged with the cylinder head 16.

7. The engine lubrication system 12 as claimed in claim 6 further includes a fourth passage 30 extending downwardly from the cavity portion 22.
8. The engine lubrication system 12 as claimed in claim 7, wherein the fourth passage 30 is positioned on the cylinder head 16 and extends to a chain tensioner.

Dated this 31st day of January, 2014 P.H.D.RANGAPPA
IN/PA-1538
OF K & S PARTNERS
AGENT FOR THE APPLICANT

,TagSPECI:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10 and rule 13]

“ENGINE LUBRICATION SYSTEM”

NAME AND ADDRESS OF THE APPLICANT:
TATA MOTORS LIMITED, an Indian company having its registered office at Bombay House, 24 Homi Mody Street, Hutatma Chowk, Mumbai - 400 001, Maharashtra, INDIA.

Nationality: Indian

The following specification particularly describes the disclosure and the manner in which it is to be performed.
TECHNICAL FIELD
The present disclosure generally relates to internal combustion engines, and relates more particularly to an oil flow passage in fluidic communication with an oil gallery within an internal combustion engine.

BACKGROUND OF THE DISCLOSURE
Internal combustion engines typically include an engine block having one or more cylinders, and a cylinder head attached to the cylinder block to close a top of the cylinders. The engine block and the cylinder head are generally cast parts made up of aluminum cast iron, or the like. Generally in the cylinder head design, the lower half of the cam bearing is integral part of the head, and the upper half is mounted on to the head.
In the conventional method of supplying oil to various parts mounted on the cylinder head, several holes are required to be drilled in the cylinder head, to form drilled oil passages.

The oil rising up from the cylinder block is required to be guided through these drilled oil passages. But this method has many disadvantages for example; higher number of drilling operations may be required for supplying oil to all the required parts. This results in relatively high machining cost, which is obviously undesirable.

The time required for machining these holes is also considerably higher. To make provision for large number of drilled holes in the cylinder head, the cast part also has to be manufactured accordingly. This increases the complexity and weight of the cylinder head. Many of the drilled holes are required to be plugged at one end. For plugging the drilled holes, sealing plugs are used, which again adds to the weight and cost of the engine.

Further, there is always a possibility of oil leakage through the sealing plugs. Increase in pressure drop also takes place due to several oil galleries, bends and junctions. Moreover, increased oil pump capacity is required to compensate for the increased pressure drop. Furthermore, higher cleanliness is required due to complicated oil galleries, which reduces engine life.
OBJECTS OF THE DISCLOSURE
One objective of the present disclosure is to provide a safe, simple, clean, reliable engine lubrication system.

Another objective of the present disclosure is to provide an engine lubrication system that effectively reduces the number of drilling operations required for supplying oil to the required parts in the engine.

Yet another objective of the present disclosure is to provide an engine lubrication system that reduces machining time by reducing the number of holes, and that uses fewer number of sealing plugs.

Another objective of the present disclosure is to provide an engine lubrication system that makes sure that the oil pressure drop due oil galleries, bends and junctions is reduced. .

Further objectives and features of the disclosure will become apparent from the following detailed description when considered in conjunction with the drawings.

SUMMARY OF THE DISCLOSURE
An engine lubrication system includes a first fluid supply passage provided on the cylinder head for communicating fluid coming from an oil sump. A camshaft bearing cap having a cavity portion is provided on the cylinder head. A first fluid supply passage is connected to the cavity; a second fluid passage is fluidically connected to the cavity portion of the camshaft bearing cap; and a third fluid passage is defined within the cylinder head and fluidically connected to the cavity portion of the camshaft bearing cap.

BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 illustrates a perspective view of an engine, in accordance to an embodiment of the present disclosure.
Figure 2 illustrates an exploded perspective view of a cylinder head of the engine of figure 1, in accordance to an embodiment of the present disclosure.
Figure 3A illustrates another perspective view of a cylinder head of the engine of figure 1, in accordance to an embodiment of the present disclosure.
Figure 3B illustrates another perspective view of a cylinder head of the engine of Figure 3A but shows internal fluid passage, in accordance to an embodiment of the present disclosure.
Figure 4 illustrates an exploded bottom perspective view of a cylinder head of the engine of figure 1, in accordance to an embodiment of the present disclosure.
Figure 5 illustrates views of a camshaft bearing cap of the engine of figure 1, in accordance to an embodiment of the present disclosure.
Figure 6 illustrates sectional side views of the cylinder head of the engine of figure 1, in accordance to an embodiment of the present disclosure.
Figure 7 illustrates a sectional perspective view of the cylinder head of the engine of figure 6, in accordance to an embodiment of the present disclosure.
Figure 8 illustrates a fluid flow diagram in the engine, in accordance to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE
Referring now to figures 1 to 8, wherein the showings are for the purpose of illustrating a preferred embodiment of the disclosure only, and not for the purpose of limiting the same.

As shown in figure 1, which is a perspective view of an internal combustion engine 10 (also referred to as “engine 10”). The internal combustion engine 10 may be a petrol or diesel engine, used for driving a vehicle such as a bus, or any other equipment.

The present disclosure describes an engine lubrication system 12 for the internal combustion engine 10. The internal combustion engine 10 comprises a cylinder head 16, cylinder block 17, and an oil sump 18 assembled in a conventional manner with, the oil sump 18 housing the oil.

The engine lubrication system 12 discloses a first fluid supply passage 14. The first fluid supply passage 14 is provided on a cylinder head 16 for communicating fluid from the oil sump 18. A camshaft bearing cap 20 is provided on the cylinder head 16. As illustrated in the figures, the camshaft bearing cap 20 is unintegral to the cylinder head 16 i.e. the camshaft bearing cap 20 is not an integral part of the cylinder head 16. On the camshaft bearing cap 20, a cavity portion 22 is defined (best shown in Figures 4 and 5). The profile of the cavity portion 22 on the camshaft bearing cap 20 may be different based on the profile of the camshaft bearing cap 20, in alternative embodiments.

The first fluid supply passage 14 is connected to the cavity portion 22 of the camshaft bearing cap 20. As per the present embodiment, the camshaft bearing cap 20 includes a bottom bearing cap 24 adapted to be connected on the cylinder head 16, and a top bearing cap 27 adapted to be connected to the bottom bearing cap 24. The cavity portion 22 is defined on the bottom bearing cap 24 of the camshaft bearing cap 20, as illustrated in figure 5. The cavity portion 22 is adapted to get sealed when the bottom bearing cap 24 is engaged with the cylinder head 16.

Referring to the figure3, a second fluid passage 26 is fluidically connected to the cavity portion 22 of the camshaft bearing cap 20 (the bottom bearing cap 24).

In one embodiment of the present disclosure, the second fluid passage 26 is an oil control valve (OCV).

A third fluid passage 28 is also defined within the cylinder head 16. The third fluid passage 28 is also fluidically connected to the cavity portion 22 of the camshaft bearing cap 20. The third fluid passage 28 is a pair of hydraulic lash adjuster (HLA) galleries.

Further, a fourth passage 30 extends downwardly from the cavity portion 22 and provides a passage to the chain tensioner.

As illustrated in FIGURE 3, the cavity portion 22 (also referred to as “oil passage”) on camshaft bearing cap 20 acts as a main feeding line for supply of oil to lubricate various parts mounted on cylinder head 16. The oil from this passage is routed to HLA oil gallery, Oil Control Valve, Chain Tensioner, intake and exhaust cam journal bearings.
Accordingly, the present disclosure provides a significant simplification of lubrication circuit for an engine and more particularly to lubrication of cylinder head, VCT, HLA, RFF and chain tensioner.

In conventional methods of lubrication for parts like OCV, HLA, which are mounted on cylinder head, complex series of drilled holes were required. These oil passage holes needed to be plugged using sealing plugs, which further added to the possibility of oil leakage. All these factors results in increasing the complexity, manufacturing cost and weight of the engine.

The present disclosure overcomes the said deficiencies and provides an engine with a simpler lubrication system inside the cylinder head which will lower the cost and complexity of the cylinder head. The technical objective of the invention is achieved by introducing a cam shaft bearing cap with a cast oil passage at its bottom, mounted on top of the cylinder head. This cam bearing cap acts as a central oil supply system, which delivers oil to various parts and thus eliminates the number of drilling operations required inside the cylinder head.

In light of the above disclosure the advantages of the engine lubrication system 12 are as follows. The engine lubrication system 12 is a safe, simple, clean, cost effective, light weight, easy to manufacture and reliable engine lubrication system. The engine lubrication system 12 effectively reduces the number of drilling operations required for supplying oil to the required parts in the engine. The engine lubrication system 12 reduces machining time by reducing the number of holes, and that uses fewer number of sealing plugs. The engine lubrication system 12 makes sure that the oil pressure drop due oil galleries, bends and junctions is reduced.

The foregoing description is a specific embodiment of the present disclosure. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from scope of the disclosure. It is intended that all such modifications and alterations be included insofar as they come within the scope of the disclosure as claimed or the equivalents thereof.

Referral Numerals:
Reference Number Description
10 Internal combustion engine
12 Engine lubrication system
14 First fluid supply passage
16 Cylinder head
17 Cylinder block
18 Oil sump
20 Camshaft bearing cap
22 Cavity portion
24 Bottom bearing cap
26 Second fluid passage
27 Top bearing cap
28 Third fluid passage
30 Fourth passage