OIL SUMP WITH BENT PIPE ACTING AS OIL RESERVOIR FOR THE OIL DRAIN LINE OF OIL SEPERATOR

Field of Invention

The present invention relates to an engine crankcase ventilation system and lubrication system having improved oil sump assembly, and more particularly to an oil separator drain provided with a bent pipe arrangement in the oil sump. The bent pipe arrangement reduces entry of oil splashing from the sump to oil separator and also prevents entry of blow by gases through the drain line in the oil sump.

Background of the Invention

In internal combustion engines, normally during the engine combustion, the combustion chamber experiences very high in-cylinder pressures and a small amount of gases in the combustion chamber escapes past the piston and piston rings. This escaped gas, usually termed as blow-by gas blows into a crank case through spaces between the pistons and the cylinders during compression and explosion strokes and includes the engine lubricating oil particulates. Usually these gases are sent to the common air filter for filtering and introduction into the engine intake for complete combustion and effective utilisation of the masses contained in the blowby gases.
In order to prevent the engine oil particulates from being introduced into the intake passage, an oil separator is provided in the blow-by gas passage formed in between the cylinder head cover and the engine intake system. The oil separator separates the oil particulates from the blow-by gas before they pass the intake system. To return the blow-by gas, a blow-by gas outlet is formed in the cylinder head cover to a downstream side of the throttle valve disposed in the intake passage. The drain line of the oil separator is connected to the engine oil sump for leading the drained oil from the blowby gases available in the oil separator to the oil sump. The oil sump is located at the bottom of the crankcase of an internal combustion engine. The oil sump holds lubricating oil to lubricate and cool moving and sliding engine parts. Oil held in the oil sump is delivered to the respective engine parts by the oil pump when the engine runs. After lubricating and cooling these engine parts, oil is collected back in the oil sump. The oil is delivered to the engine parts, which lubricates the engine components and then drops back down into the oil sump.

The oil separators have been used in internal combustion engines in order to condense and recover oil vapour circulating through crankcase ventilation systems. While it is desirable for the oil to be returned to the engine oil sump, such return of oil can also be affected by foaming due to interaction with "blowby" gases and exposure to undesirable contaminants entrained in blowby gases. Approximately 70% of these blow-by gases are unburned fuel (HC) that can dilute and contaminate the engine oil, cause corrosion to critical parts, and contribute to sludge build up. At higher engine speeds and loads, blow-by gases increase crankcase pressure that can cause oil leakage from sealed engine surfaces. Positive crankcase ventilation (PCV) system is used to remove these harmful gases from the crankcase before damage occurs and combine them with the engine's normal air intake channel.

Fig. 1 shows an oil sump assembly for an internal combustion engine having splash eliminator and baffle type reservoir for oil separator drain line, in accordance to a prior art of the invention. In a PCV system, the oil separator separates oil from blow- by gas to return the oil to the oil sump (21) through the oil discharge drain pipe (23). The oil particulates or the vaporized oil is separated from blow-by gas by the oil separator, and the separated oil is drained to the oil sump (21) through the baffle type reservoir (22). This conventional arrangement of a drain line has separate splash eliminator (24) for reducing the splashing of oil in the oil sump.

Fig. 2 shows the arrangement of a drain line of oil separator provided in the oil sump with baffle type reservoir, in accordance to prior art. The baffle reservoir (22) is placed to keep the drain connection above the oil level to facilitate the smooth entry of the oil drained from the oil separator and to avoid the possible oil entry through the drain line in the oil sump (21). Also a non-return valve is placed on the engine oil sump drain line for the oil separator to avoid backflow of blowby gases and to prevent entry of splashing oil into the drain line (23) in the oil sump.

However, the above disclosed conventional oil drain's arrangement for oil sump may not be feasible in regular and high speed engine applications. Further, the conventional oil drain arrangement in the oil sump does not prevent the turbulent engine oil splashing and rising through the drain line in the oil sump provided for the oil separator in the internal combustion engine.

Moreover, in the above prior art arrangements there is inadequate oil draining from cyclone separator as the oil splashed by crankshaft resists oil draining and rises oil through the separator drain line. This may result in the stacked up oil entering into the air intake system during higher engine speeds.

Therefore, it is desirable to provide an improved and simplified oil sump assembly for an internal combustion which overcome the disadvantages of the conventional oil drain arrangements.

Object of the Invention

The main object of the present invention is to provide an improved and simplified oil sump assembly for an internal combustion engine, eliminating the problems associated with the prior art.

Another object of the invention is to provide an oil sump assembly with oil drain arrangement from oil separator, which is simple and cost effective in construction.

Another object of the present invention is to prevent the turbulent engine oil splashing and rising through the drain line in the oil sump provided for the oil separator in the internal combustion engine.

Further object of the present invention is to eliminate the need for a non¬return valve in the engine oil sump drain line provided for the oil separator.

Further object of the present invention is to provide an oil return structure preventing oil flowing from the oil sump due to turbulent splash in the engine crankcase.
Another object of the present invention is to evade the need of separate splash eliminator in the oil sump provide with the internal combustion engine.

Summary of the Invention

The present invention which achieves the objectives relates to an oil sump assembly, having improved oil separator drain arrangement. The improved oil sump assembly includes a bent pipe which reduces oil splashing from the oil sump into oil separator drain line. The oil sump assembly has a bent pipe acting as a splash eliminator by elevating the oil drain hole and maintaining a separate column of oil within to prevent oil rising through the oil separator line ensuring reduced engine oil consumption effective cyclonic action. The invention provides an engine oil sump comprising a bent pipe to accommodate oil drained, such that the oil drain hole is kept above the engine oil level in the oil sump.

The oil sump assembly is provided with an oil sump and an oil separator having fluid communication with the oil sump. The oil drain hole from the oil separator is placed above the engine oil level in the oil sump. A bent pipe is assembled with the oil sump to accommodate the oil drained from the oil separator to the oil sump. The bent pipe elevates the oil separator oil drain hole such that the bent pipe prevents the turbulent engine oil being splashed into the oil drain hole. The bent pipe maintains a separate oil column within the oil sump, for eliminating the crankcase blow-by gases entering through the oil drain hole. The bent pipe reduces oil splashing from the sump to oil separator and also prevents entry of blow by gases through the drain line.

The oil sump is attached with the engine block with suitable assembly arrangements. In order to prevent undue pressure building up in the engine block, for example, due to blow-by gases, the crankcase ventilation line is provided to be in fluid communication between a portion of the internal engine block and the oil separator. The oil separator includes a breather element such as, a centrifugal oil separator. A mixture of oil mist and blow by gas enters into the oil separator through an oil separator inlet positioned in the vicinity of the cylinder head cover.

Oil mist/vapour that is entrained in the blow-by gases from the engine are condensed to liquid form in the oil separator due to cyclonic action, and returned to the oil sump via a drain line. The internal combustion engine also comprises the air filter in fluid communication with blow-by gas line of the oil separator. The air filter is also in communication with a compressor-turbine arrangement. The oil drain line of the oil separator is above the engine oil level in the oil sump. The crankcase pressure is monitored using a pressure gauge.

The oil sump assembly, according to the present invention allows for elimination of separate splash eliminator by replacing it with the bent pipe which simplifies the design and functions exactly as a splash eliminator in the oil sump in the internal combustion engine.

The bent pipe arrangement with the oil sump allows for preventing oil rise in the oil separator oil drain line and further oil entry into the intake manifold through a turbocharger compressor in a closed crankcase ventilation system. In addition, the engine oil consumption is reduced and effective cyclonic action is ensured inside the oil separator provided with the engine.

Brief Description of the Drawings

Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same.

Fig. 1 shows an oil sump assembly for an internal combustion engine having splash eliminator and baffle type reservoir for oil separator drain line, in accordance to a prior art of the invention.

Fig. 2 shows the arrangement of a drain line of oil separator provided in the oil sump with baffle type reservoir, in accordance to the prior art of the invention.

Fig. 3 shows a crankcase ventilation system of an internal combustion engine having an oil sump assembly with improved drain arrangement for oil separator in accordance to an exemplary embodiment of the present invention.

Fig. 4 shows the bent pipe assembled with the oil sump for drain arrangement of oil separator, in accordance to the present invention.

Fig. 5 shows the arrangement of crankcase ventilation system for internal combustion engine, in accordance to the present invention.

Detailed Description of the Invention

The present invention relates to an engine crankcase ventilation system and an oil separator drain provided with a bent pipe arrangement in the oil sump, to restrict the entry of oil splashing from the sump to oil separator and to prevent the blow by gases flowing through the drain line in the oil sump. Fig. 3 shows a crankcase ventilation system of an internal combustion engine having an oil sump assembly with improved drain arrangement for oil separator in accordance to an exemplary embodiment of the present invention. A positive crankcase ventilation system of an internal combustion engine is illustrated.

The internal combustion engine has an engine block (1), a cylinder head (2) covered by a cylinder head cover (3). The cylinder head along with the cover is assembled with the engine block. An external air-oil separator (5) is coupled with the blow-by gas passage tube for the separation of oil from the blow-by gas. An oil sump (4) is placed at the bottom of the crankcase so as to accumulate the drained oil, which has been drained and separated from the blow-by gas from the cylinder head cover and through the external oil separator (5). The engine oil sump (4) is attached to the engine block (1) with suitable fastening arrangements. In order to prevent undue pressure from building up in the engine block (1), such as, blow-by gases, crankcase ventilation line (not shown) is provided to be in fluid communication between a portion of the internal engine block (1) and the oil separator (5).

The oil separator (5) includes a breather element (not shown) or alternatively a more elaborate device, such as, for example, a centrifugal oil separator (not shown). The oil separator (5) is in fluid communication with the oil sump (4). The purified gas is discharged through the blow by gas passage tube (9) and the separated oil is discharged through the oil drain line (6). A mixture of oil mist and blow by gas enters into the oil separator (5) through an oil separator inlet (7) positioned in the vicinity of the cylinder head cover (3). Oil mist/vapour that is entrained in the blow-by gases from the engine are condensed to liquid form in the oil separator (5) due to cyclonic action, and returned to the oil sump (4) via the drain line (6).

The internal combustion engine also comprises an air filter (8) in fluid communication with blow-by gas line (9) of the oil separator (5). The air filter (8) is also in communication with a compressor-turbine arrangement (not shown). The oil drain line (6) of the oil separator (5) placed is above the engine oil level in the oil sump (4), and the crankcase pressure is monitored using a pressure gauge (not shown). The blow-by gas passage line (9) is provided with the cylinder head cover (3) so as to discharge the blow-by gas from the engine.

Fig. 4 shows the bent pipe assembled with the oil sump for drain arrangement of oil separator, in accordance to the present invention. A bent pipe (10) is fitted as an integral part of the oil drain nipple around the area of the oil drain line (6), such that an oil drain line hole (11) of the oil drain line (6) is elevated the engine oil level (12) in the oil sump (4). The bent pipe (10) also functions to replace the splash eliminator requirement in the oil sump. The bent pipe acts as a restricting wall to prevent turbulent engine oil splashing, thus the drain arrangement allows for preventing oil pushed up in the oil drain line (6) through the oil drain line hole (11). The bent pipe drain line arrangement according to the present invention also eliminates the need of a non-return valve provided inside the oil sump.

The oil that is separated from blow-by gases in the oil separator (5) enters through the oil drain line (6) into the bent pipe (12) and, in a slow, laminar manner of flow, the oil drains down from the brim of the bent pipe (10) into the oil sump (4). An oil column (12) is maintained above the oil drain line hole (11) within the bent pipe splash eliminator (12), which facilitates in preventing entry of crankcase blow-by gases into the oil drain line (6), which can otherwise reduce the efficiency of the oil separator (5). The oil from the oil column (12) is isolated from the oil separated in the oil sump (4) and is capable of flowing in a slow, laminar manner from the brim of the bent pipe splash eliminator (10) onto the oil sump (4).

In Fig. 4 the bent pipe is integrated with the oil sump assembly for drain arrangement of oil separator. The bent pipe (10) is constructed out of sheet metal and is made as an integral part of the oil drain nipple in the oil sump walls of the oil sump (4) by welding or a similar process. The position of the bent pipe can be different from that as shown. The ideal position for bent pipe is provided close to the oil separator to avoid kink in the drain hose and to have the optimum hose length. The oil sump assembly bent pipe (10) acts as a splash eliminator by elevating the oil drain hole (11) and maintaining a separate column of oil within to prevent oil rising through the oil separator line ensuring reduced engine oil consumption effective cyclonic action.

Fig. 5 shows the arrangement of crankcase ventilation system for internal combustion engine, in accordance to the present invention. An oil drain tube of the oil drain line (6) is extended, bent and immersed into the bent pipe (10) acting as splash eliminator. The blow-by gas produced in the engine (1) will flow upwards through the cylinder head (2) and enters into the blow-by gas entry passage and then flow to pass through the oil separator (5). The oil particulates are separated from the blow-by gas while the gas is passing through the oil separator (5).

In operation, the gases along with oil mist moves upward to the cylinder head cover (3) and vented to the oil separator (5) for oil separation. Oil mist/vapour that is entrained in the blow-by gases from the engine are condensed to liquid form in the oil separator due to cyclonic action, and returned to the oil sump via the drain line bent pipe arrangement (10). The oil which is collected in the oil separator (5) will get drained into crankcase oil sump (4) through the bent pipe, and the bent pipe acts as a splash eliminator and prevents entry of splashing turbulent engine oil in the crankcase into the oil separator drain line. The remaining blowby gas pass through the blowby by gas line (9) and moved into the engine intake after filtered through the engine air filter. The oil drain line of the oil separator is above the engine oil level in the oil sump. The crankcase pressure is monitored using a pressure gauge. The separated oil is get collected in an oil sump (4) through the oil drain line (6).

The oil sump assembly, according to the present invention allows for elimination of separate splash eliminator by replacing it with the bent pipe which simplifies the design and functions exactly as a splash eliminator in the oil sump in the internal combustion engine.

The bent pipe arrangement with the oil sump allows for preventing oil rise in the oil separator oil drain line and further oil entry into the intake manifold through a turbocharger compressor in a closed crankcase ventilation system. In addition, the engine oil consumption is reduced and effective cyclonic action is ensured inside the oil separator provided with the engine. The oil separation according to the present invention employs passage of blowby gas in upward and downward flow of the gas which is advantageously carried out in an extremely efficient manner, and thus providing an improved and effective oil separation arrangement for the blowby gases generated in the internal combustion engines.

The oil drain bent pipe arrangement is integrated with the drain nipple of the oil sump, and the bent pipe eliminates the need for separate splash eliminator in the oil sump, thus forming a compact and cost effective design for crankcase ventilation for the internal combustion engine.
The invention accounts for the elimination of oil rise in the oil separator oil drain line and further oil entry into the intake manifold through a turbocharger compressor in a closed crankcase ventilation system. Further, engine oil consumption is reduced and effective cyclonic action is ensured inside the oil separator.

The foregoing description is a specific embodiment of the present invention. 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 the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.

We Claim:

1. An oil sump assembly, comprises, an oil sump (4) and an oil separator (5) having fluid communication with the oil sump, wherein the oil drain hole (11) communicating the separated oil from the oil separator (5) to the oil sump (4) is placed above the engine oil level (12) in said oil sump.

wherein a bent pipe (10) is constructed to assemble with the oil sump (4) to communicate the drained oil from the oil separator (5) to the oil sump (4), and said bent pipe (10) elevates the oil separator oil drain hole (11) such that said bent pipe prevents the turbulent engine oil being splashed into the oil drain hole (11).

2. The oil sump assembly as claimed in claim 1, wherein the bent pipe (10) maintains a separate oil column within the oil sump (4), for eliminating the crankcase blow-by gases entering through the oil drain hole (11).

3. The oil sump assembly as claimed in claim 1, wherein the bent pipe (10) acts as a splash eliminator in the oil sump (4) of internal combustion engine.

4. The oil sump assembly as claimed in claim 1, wherein the oil separator (5) separates oil and air from the crankcase blow-by gases venting from the cylinder head (2).

5. The oil sump assembly as claimed in claim 1, wherein an oil drain line (6) is provided for the oil separator (5) and positioned above the engine oil level in the oil sump (4).

6. The oil sump assembly as claimed in claim 1, wherein the bent pipe (10) is fitted as an integral part of the oil drain nipple around the area of the oil drain line (6).

7. The oil sump assembly as claimed in claim 1, wherein the oil particulates and the liquid oil from the oil separator (5) enters into the bent pipe through the oil drain line (6).

8. The oil sump assembly as claimed in claim 1, wherein the oil drains down from the brim of the bent pipe (10) into the oil sump (4).

9. The oil sump assembly as claimed in claim 1, wherein the bent pipe (10) is constructed of sheet metal and is integrated with the oil sump (4) by welding or a similar process.

10. The oil sump assembly as claimed in claim 1, wherein the oil drain tube of the oil drain line (6) can be extended, bent and immersed into the bent pipe splash eliminator (10).

11. An engine lubrication system comprising an oil sump assembly as claimed in the preceding claims.

12. An engine crankcase ventilation system comprising the oil sump assembly as claimed in the preceding claims.

13. An internal combustion engine comprising the lubrication system and crankcase ventilation system as claimed in the preceding claims.