Description:A LUBRICATION SYSTEM FOR AN INTERNAL COMBUSTION ENGINE OF A VEHICLE

TECHNICAL FIELD
[0001] The subject matter in general relates to lubrication of internal combustion engine of a vehicle. The subject matter, in particular, relates to a lubrication system for an internal combustion engine of a vehicle capable of optimum utilization of pump efficiency and increased service life of relief valve.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present subject matter.
[0003] Lubrication system in an internal combustion engine helps to lubricate and cool different moving engine components. The internal combustion engine contains various moving components which are continuously subjected to surface friction. This surface friction can cause wear and tear of the moving components which may lead to decrease in life expectancy of the engine. Lubrication system uses oil for lubrication purpose. The lubrication oil creates a thin film of lubrication between the surfaces of moving components that lowers the friction between the moving components and thus the wear and tear of the engine components decreases.
[0004] In addition to lubrication, cooling of the engine moving components is also done by lubrication system. The engine works at a very high speed which results in generation of large amount of heat. Increase in the temperature of the engine, above permissible limit, may lead to engine seizing or damage to the engine. To prevent this, lubrication oil helps in carrying away the heat from the moving components of the engine and lowers the temperature of the engine to optimum temperature. For proper working of the lubrication system, lubrication oil is pumped at a certain pressure into the lubrication system. This pressure is maintained by an oil pump.
[0005] Referring to FIG. 1 illustrating oil pump of a lubrication system in accordance with the existing art. Oil pump 100 in the lubrication system is provided to raise pressure of the lubrication oil to an adequate level so that lubrication system can work properly. The oil pump 100 has an inlet 101, an outlet 102 and a relief valve 103. The inlet 101 is adapted to intake lubrication oil from oil sump. The outlet 102 is adapted to discharge lubrication oil with adequate pressure. The relief valve 103 is provided at the outlet 102 of the oil pump 101 to maintain pressure of the discharged lubrication oil within permissible limits. Generally, a spring loaded relief valve 103 is provided in the lubrication system. Spring stiffness causes the relief valve 103 to release excess pressure from the discharged lubrication oil by moving some of the discharged lubrication oil to oil sump. Oil filter (Not shown) is provided at the outlet of oil pump to remove impurities from lubrication oil
[0006] The outlet 102 of the oil pump 100 is connected to a main oil gallery for circulation of lubrication oil. The main oil gallery is in turn connected with a plurality of auxiliary galleries and a piston cooling jet gallery. The oil through the main oil gallery is further circulated into the plurality of auxiliary galleries and the piston cooling jet gallery. A plurality of hydraulic lash adjusters is provided in the auxiliary galleries to utilize oil pressure generated by oil pump to maintain continuous contact between valve and camshaft. Thus, the hydraulic lash adjusters require certain minimum oil pressure to work properly. A plurality of piston cooling jets is provided in the piston cooling jet gallery to remove excess heat from pistons of the engine. The piston cooling jets uses lubrication oil as a cooling medium.
[0007] Since the circulation of lubrication oil is done through the main oil gallery alone, there are chances that oil pressure at the farthest point of the auxiliary galleries may fall below the minimum oil pressure required for proper working of hydraulic lash adjusters due to oil leakages along the circuit and potential difference This may hamper functioning of the hydraulic lash adjusters.
[0008] In addition, the oil supply to the piston cooling jet gallery is directed from main gallery, which is a direct consumer of oil from oil pump results in increase in oil consumption. Since the relief valve is provided upstream of the outlet or filter, situation may arise wherein contaminated oil may pass through relief valve and damage the same.
[0009] Thus there is a need in the existing art to provide a lubrication system with optimum utilization of pump efficiency capable of maintaining adequate oil pressure throughout the lubrication system and increased service life of relief valve.

SUMMARY
[0010] This summary is provided to introduce concepts related to a lubrication system for an internal combustion engine of a vehicle. The concepts are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
[0011] The present subject matter relates to a lubrication system for an internal combustion engine of a vehicle. The lubrication system comprises an oil pump, a main oil gallery, a plurality of auxiliary galleries and a piston cooling jet gallery. The oil pump has an inlet and an outlet. The oil pump is adapted to intake lubrication oil from an oil sump through the inlet and discharge the lubrication oil at an adequate pressure, based on engine RPM, through the outlet of the oil pump. The main oil gallery is in connection with the outlet of the oil pump, adapted to receive lubrication oil discharged from the oil pump. The plurality of auxiliary galleries is adapted to circulate lubrication oil to operate valve train system. A connector gallery is provided to connect first end of the plurality of auxiliary galleries with the main oil gallery and a relief valve is provided at second end of one of the plurality of auxiliary galleries. The piston cooling jet gallery is adapted to circulate lubrication oil and remove excess heat from piston of the internal combustion engine. A connector gallery is provided to connect the outlet of relief valve with second end of the piston cooling jet gallery resulting in utilization of lubrication oil from the relief valve
[0012] In an aspect, the plurality of auxiliary galleries is provided with a plurality of hydraulic lash adjusters adapted to utilize lubrication oil pressure generated by oil pump to maintain continuous contact between valve and the camshaft of the vehicle.
[0013] In an aspect, the relief valve is a spring loaded relief valve.
[0014] In an aspect, relief spring of the relief valve is calibrated at minimum required oil pressure facilitating plurality of hydraulic lash adjusters to work in the plurality of auxiliary galleries of the lubrication system during engine operation.
[0015] In an aspect, the piston cooling jet gallery is fitted with spring loaded diaphragm to regulate and control oil pressure.
[0016] In an aspect, the piston cooling jet gallery is provided with plurality of piston cooling jets to remove excess heat from piston of the internal combustion engine.
[0017] In an aspect, a return gallery is provided near first end of the piston cooling jet gallery to facilitate flow of lubrication oil from the piston cooling jet gallery into the oil sump in case of increase in oil pressure than permissible limit of piston cooling jets.
[0018] In an aspect, a filter is provided at outlet of the oil pump to ensure that lubrication oil only enters the relief valve after passing through the filter.
[0019] To further understand the characteristics and technical contents of the present subject matter, a description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit the scope of the present subject matter.
[0020] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF FIGURES
[0021] The illustrated embodiments of the present disclosure will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and processes that are consistent with the subject matter as claimed herein, wherein:
[0022] FIG. 1 illustrates an oil pump of a lubrication system in accordance with the existing art; and
[0023] FIG. 2 illustrates an exemplary lubrication system that can be utilized to implement one or more exemplary embodiments of the present disclosure;
[0024] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION
[0025] A few aspects of the present disclosure are explained in detail below with reference to the various figures. Example implementations are described to illustrate the disclosed subject matter, not to limit its scope, which is defined by the claims. Those of ordinary skill in the art will recognize a number of equivalent variations of the various features provided in the description that follows.
Definitions
[0026] In the disclosure hereinafter, one or more terms are used to describe various aspects of the present disclosure. For a better understanding of the present disclosure, a few definitions are provided herein for better understating of the present disclosure.
[0027] “Adequate Pressure” may be defined, in the context of the disclosure, as a lower limit of pressure that is required by hydraulic components for proper working of the engine.
[0028] “Oil Gallery” may be defined, in the context of the disclosure, as a hollow tube provided to create passage of lubrication oil from outlet of the oil pump to the individual components of the engine that are in need of lubrication or cooling.

EXEMPLARY IMPLEMENTATIONS
[0029] While the present disclosure may be embodied in various forms, there are shown in the drawings, and will hereinafter be described, some exemplary and non-limiting embodiments, with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiments illustrated. Not all of the depicted components described in this disclosure may be required, however, and some implementations may include additional, different, or fewer components from those expressly described in this disclosure. Variations in the arrangement and type of the components may be made without departing from the scope of the claims as set forth herein.
[0030] Existing lubrication system has a main oil chamber, connected to an oil pump, through which oil is circulated in oil galleries and hydraulically operated components. Due to oil leakages along the circuit and potential difference, there are variations in oil pressure all over the lubrication system. Due to the variations in oil pressure along the circuit, sometimes it becomes difficult for the lubrication system to maintain adequate pressure all over the lubrication system which hampers functioning of the hydraulic components of engine.
[0031] Further, in the existing lubrication system, oil supply to the piston cooling jet gallery is directed from main gallery which results in increase of direct consumer for oil pump. Furthermore, situation may arise in the lubrication system when contaminated pressurised oil may pass through relief valve and damage the relief valve.
[0032] To solve the problems, a lubrication system for internal combustion engine of a vehicle, is disclosed.
[0033] FIG. 2 illustrates an exemplary lubrication system that can be utilized to implement one or more exemplary embodiments of the present disclosure. The lubrication system 200 comprises an oil pump 201, a main oil gallery 202, a plurality of auxiliary galleries 203a, 203b and a piston cooling jet gallery 204. The oil pump 201 comprises an inlet 201a and an outlet 201b. The oil pump 201 is adapted to increase pressure of the lubrication oil up to an adequate pressure to facilitate circulation of lubrication oil in the lubrication system 200. The inlet 201a of the oil pump 201 is adapted to intake lubrication oil from oil sump (not shown). The outlet 201b of the oil pump 201 is adapted to discharge the pressurized lubrication oil. A relief valve 205 is provided to maintain pressure of the discharged lubrication oil, from the oil pump 201, within the permissible limit.
[0034] The outlet 201b of the oil pump 201 is connected to the main oil gallery 202. The main oil gallery 202 is adapted to receive discharged lubrication oil from the outlet 201b of the oil pump 201. In the existing lubrication system, the main oil gallery is solely responsible for circulating lubrication oil in the plurality of auxiliary galleries and the piston cooling jet gallery. This may lead to fall in pressure of lubrication oil at certain points of the lubrication system. In the lubrication system 200, the main oil gallery 202 is adapted to circulate lubrication oil in the plurality of auxiliary galleries 203a, 203b and crankshaft galleries. The piston cooling jet gallery 204 is isolated from the main oil gallery 202. The plurality of auxiliary galleries 203a, 203b has a first end 203aa, 203ba and a second end 203ab, 203bb. In an aspect, the end near to the outlet 201b of the oil pump 201 is first end 203aa, 203ba and the end farther to the outlet 201b of the oil pump 201 is the second end 203ab, 203bb. The plurality of auxiliary galleries 203a, 203b is adapted to circulate lubrication oil to operate valve train system. A connector gallery 206 is provided to connect the first end 203aa, 203ba of the plurality of auxiliary galleries 203a, 203b with the main oil gallery 202. The connector gallery 206 creates a lubrication oil flowing path from the main oil gallery 202 to the plurality of auxiliary galleries 203a, 203b.
[0035] Provisions are provided in the plurality of auxiliary galleries 203a, 203b to accommodate a plurality of hydraulic lash adjusters (not shown). Further, the plurality of auxiliary galleries 203a, 203b are in connection with each other. The hydraulic lash adjusters are adapted to utilize oil pressure generated by oil pump 201 to maintain continuous contact between valve and the camshaft of the vehicle. The plurality of hydraulic lash adjusters requires certain minimum lubrication oil pressure for proper working and lubrication of camshaft of the vehicle.
[0036] In the lubrication system, the piston cooling jet gallery 204 is provided isolated from the main oil gallery 202. The piston cooling jet gallery 204 has a first end 204a and a second end 204b. In an aspect, the end near to the outlet 201b of the oil pump 201 is first end 204a and the end farther to the outlet 201b of the oil pump 201 is the second end 204b. The piston cooling jet gallery 204 has a plurality of piston cooling jets 207 adapted to remove excess heat from piston of the internal combustion engine. The piston cooling jets 207 uses lubrication oil from the oil pump 201 as a cooling medium to remove excess heat from piston of the internal combustion engine.
[0037] In the lubrication system 200, the problem of maintaining adequate pressure in the plurality of auxiliary galleries 203a, 203b for proper working of the plurality of hydraulic lash adjusters is solved by providing the relief valve 205 at second end 203ab of one of the plurality of auxiliary galleries 203a, 203b. The relief valve 205 is adapted to ensure that the discharged lubrication oil from the outlet of the oil pump 201 is within the permissible limit. In an aspect, the relief valve 205 used in the lubrication system 200 is a spring loaded relief valve. In the spring loaded relief valve 205, the relief spring is calibrated at minimum required oil pressure in the lubrication system 200. This ensures that an adequate pressure is maintained in the lubrication system 200 and the plurality of hydraulic lash adjusters works in the plurality of auxiliary galleries 203a, 203b of the lubrication system 200 during engine operation.
[0038] In the lubrication system 200, the problem of providing lubrication oil in the piston cooling jet gallery 204 is solved by joining the relief valve 205 with the second end 204b of the piston cooling jet gallery 204 by using a connector gallery 208. Accordingly, in the lubrication system 200, oil from the relief valve 205 is used for providing lubrication oil in the piston cooling jet gallery 204. Thus, the lubrication system 200 utilize oil from the relief valve 205, which in the existing systems, is returned to the oil sump. This ensures optimum use of lubrication oil as the oil which was previously dumped into the oil sump is now utilized in the lubrication system 200 and also optimization of pump work. In addition, the piston cooling jet gallery 204 is fitted with spring loaded diaphragm to regulate and control oil pressure.
[0039] In the lubrication system 200, the problem of damage to the relief valve 205 due to passing of contaminated lubrication oil is solved by providing relief valve 205 at the second end 203ab of one of the plurality of auxiliary galleries 203a, 203b. This ensures that lubrication oil only enters the relief valve 205 after passing through a filter provided at outlet 201b of the oil pump 201.
[0040] A return gallery 209 is provided near first end 204a of the piston cooling jet gallery 204 to facilitate flow of lubrication oil from the piston cooling jet gallery 204 to the oil sump.
WORKING OF THE LUBRICATION SYSTEM FOR AN INTERNAL COMBUSTION ENGINE OF A VEHICLE
AT LOW ENGINE RPM
[0041] At low engine RPMs, the inlet 201a of the oil pump 201 intakes lubrication oil from the oil sump. The oil pump 201 discharges the lubrication oil at adequate pressure from the outlet 201b of the oil pump 201. At low engine RPMs the elevated pressure of the lubrication oil is within permissible limit because oil pump 201 elevate pressure of the lubrication oil based on the engine RPM. Further, at low engine RPMs there is no need to provide lubrication oil to the piston cooling jet gallery 204 as the temperature of the piston is maintained within the permissible limit. Oil discharged from the outlet 201b of the oil pump 201 is introduced into the main oil gallery 202. From the main oil gallery 202, the lubrication oil is introduced to the crankshaft and plurality of auxiliary galleries 203a, 203b. The plurality of hydraulic lash adjusters utilize the oil introduced into plurality of auxiliary galleries 203a, 203b to maintain continuous contact between valve and the camshaft of the vehicle. In this way, the camshaft of the vehicle is lubricated.
AT HIGH ENGINE RPM
[0042] At high engine RPMs, the inlet 201a of the oil pump 201 intakes lubrication oil from the oil sump. The oil pump 201 discharges the lubrication oil at adequate pressure from the outlet 201b of the oil pump 201. At high engine RPMs, the elevated pressure of the lubrication oil is not always within permissible limit because oil pump 201 elevate pressure of the lubrication oil based on the engine RPM. Thus, situation may occur wherein the discharging pressure, of the lubrication oil, may be higher than required. Further, at high engine RPMs, there is a need to provide lubrication oil to the piston cooling jet gallery 204 as the temperature of the piston may increase above the permissible limit. Oil discharged from the outlet 201b of the oil pump 201 is introduced into the main oil gallery 202. From the main oil gallery 202, the lubrication oil is introduced into the plurality of auxiliary galleries 203a, 203b. In case the relief valve 205 comes into play due to pressure of discharged lubrication oil being more than permissible limit, lubrication oil from the relief valve 205 is introduced into the piston cooling jet gallery 204 through second end 204b of the piston cooling jet gallery 204. In this way, the lubrication system 200 utilizes lubrication oil from the relief valve 205 for lubrication of pistons of the internal combustion engine. Relief valve is calibrated such that excess oil after required minimum oil pressure in auxiliary galleries, discharged to piston cooling jets gallery This helps in maintaining adequate oil pressure at all points of lubrication system in all operating conditions.
ADVANTAGES
[0043] The proposed lubrication system ensures maintainence of adequate oil pressure throughout the lubrication system in all operating conditions. The proposed lubrication system utilizes lubrication oil from the relief valve resulting in efficient use of oil pump for lubrication . The proposed lubrication system prevent relief valve failure due to intake of contaminated lubrication oil by changing location of relief valve after oil filter
[0044] The above description does not provide specific details of the manufacture or design of the various components. Those, of skilled in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.
[0045] Further, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.
[0046] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.
[0047] It will be appreciated that variants of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
, Claims:We Claim:
1. A lubrication system (200) for an internal combustion engine of a vehicle, the system (200) comprises:
an oil pump (201) having an inlet (201a) and an outlet (201b), wherein the oil pump (201) is adapted to intake lubrication oil from an oil sump through the inlet (201a) and discharge the lubrication oil at an adequate pressure, based on engine RPM, through the outlet (201b) of the oil pump (201);
a main oil gallery (202) in connection with the outlet (201b) of the oil pump (201), adapted to receive lubrication oil discharged from the oil pump (201);
a plurality of auxiliary galleries (203a, 203b) adapted to circulate lubrication oil to operate valve train system, wherein a connector gallery (206) is provided to connect first end (203aa, 203ba) of the plurality of auxiliary galleries (203a, 203b) with the main oil gallery (202) and a relief valve (205) is provided at second end (203ab) of one of the plurality of auxiliary galleries (203a, 203b); and
a piston cooling jet gallery (204) adapted to circulate lubrication oil and remove excess heat from piston of the internal combustion engine, wherein a connector gallery (208) is provided to connect the outlet of relief valve (205) with second end (204b) of the piston cooling jet gallery (204) resulting in utilization of lubrication oil from the relief valve (205).
2. The lubrication system (200) as claimed in claim 1, wherein the plurality of auxiliary galleries (203a, 203b) are provided with a plurality of hydraulic lash adjusters adapted to utilize lubrication oil pressure generated by oil pump (201) to maintain continuous contact between valve and the camshaft of the vehicle.
3. The lubrication system (200) as claimed in claim 1, wherein the relief valve (205) is a spring loaded relief valve.
4. The lubrication system (200) as claimed in claim 2, wherein relief spring of the relief valve (205) is calibrated at minimum required oil pressure facilitating plurality of hydraulic lash adjusters to work in the plurality of auxiliary galleries (203a, 203b) of the lubrication system (200) during engine operation.
5. The lubrication system (200) as claimed in claim 1, wherein the piston cooling jet gallery (204) is fitted with spring loaded diaphragm to regulate and control oil pressure.
6. The lubrication system (200) as claimed in claim 1, wherein the piston cooling jet gallery (204) is provided with plurality of piston cooling jets (207) to remove excess heat from piston of the internal combustion engine.
7. The lubrication system (200) as claimed in claim 1, wherein a return gallery (209) is provided near first end (204a) of the piston cooling jet gallery (204) to facilitate flow of lubrication oil from the piston cooling jet gallery (204) into the oil sump in case of increase in oil pressure than permissible limit of piston cooling jets.
8. The lubrication system (200) as claimed in claim 1, wherein a filter is provided at outlet (201b) of the oil pump (201) to ensure that lubrication oil only enters the relief valve (205) after passing through the filter.