FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
Cylinder crankcase ventilation system and System for oil separation from blow
by gas for IC engines.
APPLICANTS
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS
Mr. Narendra Kumar Jain, Mr. Hemant Ambadas Malekar Mr. Mangesh Tukaram Nimbalkar and Mr. Kedar Digambar Gokhale
all Indian nationals
of TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in
which it is to performed.

FIELD OF INVENTION:
This invention relates to cylinder crankcase ventilation system in IC engine, more particular to cylinder crankcase ventilation system and oil separation from blow by gas in two cylinder and 360 crank disposition, used in the internal combustion engine and more particular to a four stroke Gasoline / Diesel / LPG / CNG / Ethanol / Methanol / Multi point fuel injection gasoline and diesel direct injection / Gasoline direct injection, reciprocating piston, naturally aspirated / supercharged / turbocharged / turbocharged inter-cooled and double overhead camshaft engine, intended for passenger car, light commercial vehicle and other transport / mobile / stationary applications.
BACKGROUND OF INVENTION:
In an internal combustion engine, a certain amount of leakage of fully or partly combusted exhaust gases always occur between the piston rings and the cylinder wall to the crankcase during the compression steps of the combustion engine. This exhaust gas leakage is generally referred to as blow-by, the gases also contain condensate from the engine oil in the crankcase. To meet emission regulations requirements in order to prevent unfiltered exhaust gases from being discharged directly to the environment, these exhaust gases are ventilated to the intake system of the engine for combustion in the cylinders. This principle is generally referred to as PCV, Positive Crankcase Ventilation.
Improper crankcase ventilation system may cause excess oil carry over along with blow by gases. The excess oil may cause spark plug electrode burning / fouling leading to misfire & catalytic converter damage.
In case of passenger carrying vehicles with SI engines the emissions regulations demands for, cylinder crankcase pressure to be below atmospheric under specified operating conditions.

Hence it is very much important to have efficient crankcase ventilation system & system for separating oil from ventilation gases meeting regulatory requirements. The subject invention describes an efficient, compact, low cost crankcase ventilation systemand a system to separate oil from these gases and also meeting regulatory requirements.
In conventional 4 cylinder and 3 cylinder engines, crankcase ventilation systems are well established. In case of a four cylinder engine two pistons move up and two piston move down at the same time hence pressure inside crankcase is almost balanced, Similar case for two cylinder 180 crank disposition engines. However, with 360 degree disposition of cranks, both piston moves up and down simultaneously hence higher crankcase fluctuating pressures are created. As per emissions regulations for passenger carrying vehicles, in gasoline engines the crankcase pressure should be below atmospheric pressure under specified operating conditions. Also as both pistons moves up and down simultaneously, it causes higher displacement of gas volume in crankcase, therefore higher amount of ventilation gases and higher amount of oil carry over along with ventilation gases are encountered by ventilation system. Hence in case of a two cylinder engine with 360° crank disposition, crankcase ventilation and low oil carry over in ventilation gases is a challenging task
The invention described herein relates to a simple cost effective system for crankcase ventilation, meeting regulation and less amount of oil carry over in the ventilation gases built inside the engine itself using crankcase, cylinder head & cover cylinder head of the engine.
This invention will serve the diverse requirements of passenger cars as well as those of light commercial vehicles at the least cost by leveraging the expertise available and applying lean manufacturing methods.

PRIOR ART:
United States Patent 5852992 describes a internal combustion engine includes separated oil drain-back and crankcase ventilation passages. The oil drain-back passages extend from the cylinder head to a position below the top level of oil in the engine's crankcase. The crankcase ventilation passages extend from passages formed in the main bearing bulkheads from positions above the oil level in the crankcase and ultimately through the cylinder head. Oil dams surrounding the uppermost portions of the crankcase ventilation passages prevent oil from running downwardly through the crankcase ventilation passages.
Above system is conventional system. This prior art system does not contain non return valve, dedicated passages for gas & oil & a vertical oil separator inside crankcase which are used in the present invention.
US Patent 5617834 describes a clear base ventilation system for an internal combustion engine includes an air-oil separator. Blowby gas from the engine crankcase is drawn into the inlet of the separator in a swirling cyclonic motion so as to force any oil entrained in the blow by gas to impinge on the walls of the inlet and drain back into the crankcase. Blow by gas is then drawn into a baffle which further removes any entrained oil in the blow by gas as the gas flows there through. An outlet chamber exists at the end of the baffle and has a volume of space substantially greater than the volume of space in the baffle such that blow by gas flowing out of the baffle reduces in speed, thereby allowing any further entrained oil to separate from the blow by gas. Substantially oil-free gas is then introduced to the air induction system of the engine.
The system uses separator with swirling cyclonic motion. The subject invention does not use such system.

This prior art system does not contain non return valve, dedicated passages for gas, oil & a vertical oil separator inside crankcase which are used in the present invention.
United States Patent 5450835 describes an oil separator for reducing oil carryover from the vent port of the crankcase of an internal combustion engine, such as a diesel engine is provided. The separator includes a cylindrical housing filled with a filtration material and having both an inlet and an outlet in its upper portion and a downwardly disposed, frustro-conical wall that defines an annular chamber between its outer surface and the inner walls of the housing. The annular chamber defines a helical flow path through the filtration material in the housing for a stream of oil-laden air admitted through the inlet of the housing. Oil droplets are removed from the stream of air as it moves through the helical path both by impingement against the filtration material, and the by centrifugal impingement against the inner walls of the housing. At the end of the helical path, the stream of air is directed along a hairpin turn through an opening in the frustro-conical wall and from there into a double-back path before exiting the housing, thereby removing still more entrained oil droplets. The resulting filtered stream of air may be directed into the engine draft tube or the air filter by means of a pipe. The separator also includes an oil drain conduit for conducting liquid oil collected by the filtration material into the oil pan of the engine at a level lower than the operating level of the oil within the pan for uninhibited drainage.
This prior art system does not contain non return valve, dedicated passages for gas, oil & a vertical oil separator inside crankcase which are used in the present invention.
US Patent 5579744 describes a crankcase ventilating system for an internal combustion engine includes a vent line issuing from the crankcase and connected to a liquid separator. The liquid separator has a collecting chamber for separated liquid

and at least two drain lines returning to the crankcase. The liquid separator also has a connection leading to the vacuum line of the internal combustion engine. This prior art does not contain non return valve, dedicated passages for gas, oil & a vertical oil separator inside crankcase which are used in the present invention. Moreover, this prior art system uses external separator than inbuilt separator in the engine as is the case of present invention.
OBJECTS OF THE INVENTION:
A) The main object of the invention is to have low cost, compact cylinder crankcase
ventilation system and system for oil separation built inside the engine using
crankcase, cylinder head, cover cylinder head passages for two cylinder internal
combustion engine with 360° crank disposition with following features
1) To meet regulatory requirement for pressure inside crankcase below atmosphere.
2) To have minimum oil carry over along with crankcase gases, thereby reducing oil consumption.
3) To have optimum amount of blow by gas flow rates.
4) Recirculation of crankcase gases for combustion in the engine.
5) Use of internal parts & passages inside engine for ventilation & oil separation system
6) Maximum utilization of space available within engine crankcase.
7) Minimum number of parts.
B) To have cylinder crankcase ventilation system & system for separation of oil from
the ventilation / blow by gases for an Internal combustion engine used in passenger
cars, light commercial vehicles and other transport / mobile/ stationary applications.

C) To have cylinder crankcase ventilation system & system for separation of oil from the ventilation / blow by gases for two cylinder Internal combustion engine with 360° crank disposition & 180° crank disposition.
D) To have cylinder crankcase ventilation & oil separation system for an internal combustion engine adoptable for various alternate fuels viz. Ethanol, Methanol, Gasohol Diesel, Gasoline, Liquid Petroleum Gas (LPG), Compressed Natural Gas (CNG), Hydrogen (H2) and suitable for single fuel / bi-fuel / multi-fuel operation.
E) To have cylinder crankcase ventilation & oil separation system for an internal
combustion engine that can be naturally aspirated, selectively supercharged /
turbocharged and/or intercooled depending on the application requirements.
F) To have cylinder crankcase ventilation & oil separation system for an internal
combustion engine that can be adoptable for hybrid vehicle applications / operation.
BRIEF DESCRIPTION OF INVENTION:
According to the present invention, the cylinder crankcase ventilation & oil separation from ventilation gas / blow by gas is designed for a four-stroke reciprocating piston internal combustion spark/ compression ignition engine & uses a simple reed plate as non return valve, an innovative oil separator in the crankcase & oil separator in the cylinder head cover.
The system consist of a
Ventilation / Blow by Gas pick up location inside cylinder crankcase.
An oil separation device placed inside the cylinder crankcase.
A non-return valve to maintain cylinder crankcase pressure below atmospheric.
Oil separation mechanism post non-return valve.

a. Arrangement to drain separated oil back to oil sump.
b. Arrangement for recirculation of blow by gases for combustion in the engine.
The system uses dedicated ventilation passage for crankcase gases provided at rear
of crankcase and dedicated oil return passage provided at front side of cylinder
crankcase.
Crankcase gases are tapped in the zone where mixing of oil with crankcase gases is
minimum. The ventilation passage at rear side is closed from all ends except for a
passage to allow blow-by gases to avoid mixing of oil with crankcase gases. A reed
plate non return valve is provided in ventilation gas passage in the cylinder. The non
return valve is optimized in such a way that the cylinder crankcase pressure is below
atmospheric pressure in various operating conditions. The gas flow rate is controlled
by optimizing the size of non return valve, entry & outlet passage in the cover
cylinder head.
Further the oil carried with crankcase gases is separated in three stages. In the 1st
stage a compact, oil separator is placed inside the passage for crankcase ventilation
in.the cylinder block. In this, the crankcase gases enter into separator at one end and
separated oil is drain back to oil sump from other end.
In the second stage oil is separated from crankcase gases in the ventilation passage
inside cylinder head. A similar oil separator as in the 1st stage is used to separate oil
from crankcase gases. This is an optional separator, which can be used if quantity of
oil carry over in gases is high.
In 3rd stage oil is separated from crankcase gases inside the cylinder head cover.
Baffles are provided inside cylinder head cover. A drain passage is provided on
baffle plate to direct separated oil to drain tube fixed on baffle plate. The separated
oil is drained to back to cylinder head.
A separate oil drain passage is provided inside cylinder head and cylinder crankcase.
The oil drain tube provided in cylinder crankcase to drain oil in the cup in the oil
sump, to ensure oil is always drained below oil level in all operating conditions.

SUMMARY OF INVENTION:
The present invention discloses a low cost, compact system for ventilating cylinder crankcase gases and separating oil that is carried by blow-by gases and returning the separated oil back to oil sump. When piston moves down the crankcase gases are ventilated through a dedicated passage in crankcase. A dedicated ventilation passage is provided in the cylinder crankcase. This passage is sealed by a cover to avoid mixing of oil with gases.
The gases then pass through dedicated passage at rear side of cylinder head. A reed plate mounted on cylinder head above dedicated ventilation passage, acts like a non return valve. This non return valve helps in maintaining average negative pressure inside crankcase and oil sump. The gases from cylinder head enters into cylinder head cover top portion which is sealed by baffle plate. The outlet of cylinder head cover is connected to clean air hose through a hose pipe. These gases are mixed with clean air and flow to combustion, chamber. Thus crankcase gases are recirculated to combustion chamber.
The system preferably consists of three stage oil separator to separate carry over oil from, the ventilation / blow by gases.-
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT:
Reference to the drawings for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same, Figure (1) shows cross section of engine at rear side of engine. Figure (2) shows cross section of engine along engine axis. Figure (3) shows cross section of engine at front side of engine.

N ow with reference to figures, Figure (1) shows cylinder crankcase (1) with a row of cylinders, location for ventilation gas pick up (2), oil separator (3) inside the cylinder crankcase (1), cylinder head (4), Non return valve (reed plate type) (5), cylinder head cover (6), ventilation (blow by) gas entry (7) to cylinder head cover (6), Ventilation (blow by ) gas out (8) from cylinder head to engine intake, Gas path (9), oil return line (10), dedicated ventilation gas passage (11) inside cylinder head (4) for addition oil separator. The oil separators can be optional also.
Figure (2) shows cylinder crankcase (1), location (2) for ventilation gas pick up, oil separator (3), cylinder head (4), Non return valve (reed plate type) (5), cylinder head cover (6), Blow by gas entry (7) into cylinder head cover (6), oil separation baffles (13) inside cylinder head cover (6), Separated oil return tube (14), Blow by gas path (11), oil return path (15), rear cover (12), compacted wire mesh block (21), front cover(17) Figure (3) shows cylinder crankcase (1), cylinder head (4), cylinder head cover (6), oil sump (18), oil return passage (15) from cylinder head cover (6), oil return tube (20) inside cylinder block, returned oil collector (19) inside sump (18),.
Referring to figures, the system uses a dedicated ventilation passage (11) for crankcase gases provided at rear side (a) of the engine and a dedicated oil return passage (15) at front side (b) of the engine i.e one end of the row of cylinders. Crankcase gases are tapped in the ventilation gas pick-up zone (2) where mixing of oil with crankcase gases is minimum. The dedicated blow-by gas ventilation passage (11) is formed to carry the blow by gases by the cylinder crankcase (1) and rear cover (12). This passage (11) is in communication with the crankcase passage with an oil separator (3) located inside. The separator (3) is an independent part with specifically designed baffles to separate oil. The oil separator is partially open structure having rear and side walls. The lower portion of structure is having a gas entry point and other end having an oil return line attached to it. An oil return path provided near the side wall proximal to the oil return line. Series of baffles located between the side

walls attached to the rear wall. Every alternate baffles are extended to the side wall and the baffles between the above baffles having extended leg in the direction of oil return path and leaves a gap with above side walls. This shape will help in circulating the gas between the baffles. The baffles which are extended the side wall having other end located in oil return path on opposite side. The extended leg of adjacent baffles opens a gap to the oil return path so that oil separated between the baffles is directed through the oil return path.
The dedicated oil return passage (15) is provided to drain oil back to oil sump (18). The separator (3) is firmly placed inside the dedicated blow-by gas ventilation passage (ll)and can be removed when required. The cylinder head (4) mounted above the cylinder block is having a blow by gas entry passage (7) at its rear side (i.e one end of the row of cylinders) which is connected to the dedicated blow-by ventilation passage (11) in crankcase (1) and carries the blow by gases. The said gas entry passage (7) is a closed passage and can also accommodate a second oil separator (similar to one used inside cylinder crankcase). Depending on engine configuration either one of the oil separators can be used or both oil separators can be used. The oil separated by these oil separators is guided back to the oil sump (18) through passage inside oil separator (3). At the end of the dedicated ventilation passage (11) at the top portion of cylinder head (4) a reed plate type non return valve (5) is provided so that a pressure in the cylinder crankcase (1) is maintained below atmosphere pressure.
The cylinder head cover (6) is provided with the gas entry passage (7) to receive blow by gases passing through non return valve (5). In a further oil separating stage, the blow by gasses are directed through oil separating baffles (13) provided inside the cylinder head cover (6). The outlet (8) of cylinder head cover (6) is connected to a clean air hose through a hose pipe (not shown). These gases are mixed with clean air

and flow to combustion chamber (not shown). Thus crankcase gases are re-circulated to combustion chamber.
The oil separated using baffles (13) in cylinder head cover (6) flows through portion (c) provided on the baffle plate (16). This baffle plate separate gas passage with the cam area. The oil is returned to cam area inside cylinder head through a "U" shaped, separated oil return tube (14) welded to baffle plate (16). The separated oil and the oil inside cam area of cylinder head (4) is returned to the oil sump (18) through a dedicated oil return path (15) in the cylinder head (4), and crankcase (1) located at front side (b) of the engine i.e other end of the row of cylinders. The dedicated oil return path (15) is further fluidly connected to a passage formed by crankcase and front cover (17). This dedicated oil return passage (15) is connected to an oil collector (19) placed in the oil sump (18) through an oil drain tube (20) mounted on cylinder crankcase. The oil collector (19) is placed below oil level in the sump (18).
The blow by gases are tapped and passed through the dedicated blow-by gas ventilation passage (11) located at rear side of the engine in crankcase (1), cylinder head (4) and then cylinder head cover (6). The oil is separated from blow by gases by oil separators (3) located in cylinder crankcase passage, cylinder head passage and by baffles (13) inside cylinder head cover (6). The separated oil and oil in the cam area is returned to oil sump (18) through a dedicated oil return path (15) provided at front side of engine through cylinder head (4), crankcase (1) and a passage formed by crankcase and front cover.
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. A crankcase ventilation and oil separating system for an Internal combustion
engine having cylinder block provided with a row of cylinders and a crankcase
formed in a bottom thereof having series of bearing walls holding a crankshaft, an oil
sump located below said crankcase, a cylinder head and a cylinder head cover
comprising;
a blow by gas passage formed in said cylinder block and in said cylinder head and
located at first end of said row of cylinders, communicating with said crankcase and
said cylinder head cover for discharging blow by gases out of said crankcase there
through;
said cylinder head cover having a passage with oil separation baffles communicating
with said blow by gas passage; and
an oil return passage formed in said cylinder head and in said cylinder block and
located at second end of said row of cylinders, communicating with said cylinder
head cover passage and said oil sump for returning the separated oil back to said oil
sump.
2. A crankcase ventilation and oil separation system as claimed in claim 1 wherein the bottom of said blow by gas passage is provided with a blow by gas entry line communicating with said crankcase gas pick up zone where the mixing of oil with crankcase is minimum and an oil return line communicating with said oil sump for returning oil separated in said passage.
3. A crankcase ventilation and oil separating system as claimed in claim 2 wherein said gas entry line and oil return line are formed in crankcase outer wall with an outer cover.

4. A crankcase ventilation and oil separating system as claimed in claim 1 wherein top of said blow by gas passage in cylinder head is provided with a reed valve.
5. A crankcase ventilation and oil separating system as claimed in claim 1 wherein at least one oil separation device located in said blow by gas passage.
6. A crankcase ventilation and oil separating system as claimed in claim 1 wherein said cylinder head cover passage having a inlet for receiving blow by gas , an outlet connected to air intake area to recirculate the cleaned air for combustion, series of oil separation baffles positioned on a baffle plate for separating oil from the blow by gas directed through said baffles and an U shaped oil return tube connected to said baffle plate for draining oil separated in the baffle plate communicating with said oil return passage.
7. A crankcase ventilation and oil separating system as claimed in claim 6 wherein said baffle plate separating said gas passage from the cam area of said engine.
8. A crankcase ventilation and oil separating system as claimed in claim 1 wherein said oil return passage is connected to an oil collector placed in said oil sump through an oil drain tube mounted on said cylinder crankcase.
9. A crankcase ventilation and oil separating system as claimed in claim 8 wherein said oil collector is placed below the oil level in said oil sump.

10. A cylinder crankcase ventilation and oil separating system for an internal combustion engine substantially as hereinabove described with reference to the accompanying drawings.