OIL SUMP WITH SPLASH ELIMINATOR

Field of Invention

The invention relates to an improved engine oil sump, preferably an oil sump for an engine lubrication system and more particularly relates to a drain arrangement in an oil drain line of a cyclone separator in an engine crankcase ventilation system.

Background of the Invention

During normal engine combustion, 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. 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. A 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.

In a positive crankcase ventilation system according to a prior art, the oil separator's oil drain connection is normally kept below the oil level in the oil sump. A check valve would be required while keeping the drain connection above the oil level to avoid blow-by gas and/or oil entry through the drain line.

In an arrangement of a drain line without a check valve, a defect-prone rubber diaphragm in the cyclone separator can cause the oil from the drain line to be sucked as the vacuum acts uncontrollably on the drain line.

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. Further, this may result in the stacked up oil entering into the air intake system during higher engine speeds.

Object of the Invention

An object of the invention is to prevent oil splashing and rising through the drain line.

A further object of the invention is to avoid use of a non-return valve in the drain line.

Summary of the Invention

In order to achieve the above-mentioned objects, the invention provides an engine oil sump comprising a splash eliminator, such that the oil drain hole is kept above the engine oil level in the oil sump. The splash eliminator forms a wall near the oil separator oil drain hole thereby preventing the turbulent engine oil being splashed into the oil drain hole. The splash eliminator maintains a separate oil column above the oil drain hole, thereby eliminating crankcase blow-by gases entering through the oil drain hole thereby increasing the cyclone effectiveness of the oil separator.

The advantage of the arrangement according to the instant invention is 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 splash eliminator is constructed in the form of a baffle reservoir. Further, the oil drain line can be extended, bent and immersed in the baffle reservoir.

Statement of Invention

Accordingly, the invention described herein relates to an oil sump comprising a splash eliminator positioned in a vicinity of an oil drain line; said oil drain line having an oil drain line hole being positioned above oil level in said oil sump; and said splash eliminator provides a separate oil column above the regular sump engine oil level.

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:

Figure 1 shows a normal crankcase ventilation system of an internal combustion engine,

Figure 2A shows a splash eliminator in an oil sump according to the present invention, and

Figure 2B shows the cross sectional view of the splash eliminator in an oil sump according to the present invention.

Detailed Description of the Invention

A typical crankcase ventilation system of an internal combustion engine is illustrated in figure 1. The internal combustion engine, generally indicated at 10, includes an engine block (1), a cylinder head portion (2) covered by a cylinder head cover (3) and attached with the engine block using bolts or the like (not shown). The engine also comprises an oil sump (4) also attached to the engine block (1) with suitable arrangement. In order to prevent undue pressure from building up in the engine block (1), for example, due to blow-by gases, a crankcase ventilation line (not shown) may be provided to be in fluid communication between a portion of the internal engine block (1) and an oil separator (5). The oil separator (5) may include 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). A mixture of oil mist and blow by gas enters into the oil separator 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 a drain line (6a). 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 (11) as shown in figure 1.

As illustrated in figure 1, the oil drain line (6a) of the oil separator (5) is above the engine oil level in the oil sump (4). The crankcase pressure is monitored using a gauge indicated by (P).

Figure 2A and 2B illustrates the oil sump (4) according to the present invention. A splash eliminator (12), preferably in the form of a baffle reservoir is fitted around the area of the oil drain line (6a), such that an oil drain line hole (6b) of the oil drain line (6a) is kept above the engine oil level (14) in the oil sump (4). The splash eliminator acts as a restricting wall to prevent turbulent engine oil splashing. Thus, with this arrangement oil is not pushed up in the oil drain line (6a) through the oil drain line hole (6b) and also use of a non-return valve inside the oil sump is avoided. The oil that is separated from blow-by gases in the oil separator (5 of fig 1) enters through the oil drain line (6a) into the splash eliminator (12) and, in a slow, laminar manner of flow, the oil drains down from the brim of the splash eliminator (12) into the oil sump (4).

Further, as illustrated in figure 2B an oil column (13) is maintained above the oil drain line hole (6b) within the splash eliminator (12), which facilitates in preventing entry of crankcase blow-by gases into the oil drain line (6a), which can otherwise reduce the efficiency of the oil separator (5 of fig 1). Oil from the oil column (13) is isolated from the oil (15) in the oil sump (4) and, as mentioned earlier, is capable of flowing in a slow, laminar manner from the brim of the splash eliminator (12) onto the oil sump (4).

The splash eliminator (12) is preferable constructed out of sheet metal and is fitted to the walls of the oil sump (4) by welding or a similar process.

The position of the splash eliminator can be different from that as shown in figure 2A. However, the suggested ideal position should be close to the oil separator to avoid any kink in the drain hose and to have the optimum hose length.

An oil drain tube of the oil drain line (6a) can be extended, bent and immersed into the splash eliminator (12).

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.

While the above paragraphs explain the various embodiments of the invention, it is apparent that numerous modifications and variations can be made without departing from the scope and spirit of this invention.

WE CLAIM

1. An oil sump (4) comprising:

a splash eliminator (12) positioned in a vicinity of an oil drain line (6a);

said oil drain line (6a) having an oil drain line hole (6b) being positioned above regular engine oil level (14) in said oil sump (4); and

said splash eliminator (12) is provided with a separate oil column (13) above said oil drain line hole (6b).

2. The oil sump as claimed in claim 1, wherein said splash eliminator (12) is constructed in the form of a baffle reservoir.

3. The oil sump as claimed in claim 1, wherein oil from said oil column (13) is isolated from oil (15) in said oil sump (4) and is capable of flowing in a slow, laminar manner from the brim of the splash eliminator (12) onto the oil sump (4).

4. The oil sump as claimed in claim 1, wherein said splash eliminator (12) is constructed out of sheet metal and is fitted to the walls of said oil sump (4).

5. The oil sump as claimed in claim 1, wherein a hose tube of said oil drain line (6a) can be extended, bent and/or immersed into said splash eliminator (12).

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

7. An internal combustion engine comprising an engine lubrication system as claimed in claim 6.