FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003
COMPETE SPECIFICATION
(See Section 10 and Rule 13)
OIL MIST PRE-SEPARATOR
FLEETGUARD FILTERS PRIVATE LIMITED
An Indian Company having registered address at: 136, Park Marina Road, Baner, Pune - 411 045, MH, India
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

TECHNICAL FIELD
[0001] The present disclosure relates generally to an oil separator, and more specifically to an oil mist pre-separator.
BACKGROUND
[0002] During the operation of internal combustion engines, blow-by gas leaks from the engine and enters into the crankcase of the respective internal combustion engine. To avoid emission of blow-by gas into the environment, a crankcase ventilation system is used. Also, oil mist is generated during operation of the internal combustion engines. Thus, exhausted blow-by gas contains oil mists. To prevent the pollutant emission of the internal combustion engine, the crankcase ventilation system normally uses an oil mist separator to separate the oil mist carried along with the blow-by gas sucked out of the crankcase and to convey it to a suitable oil reservoir. Normally, the oil reservoir may involve an oil pan attached at the bottom of the crankcase.
[0003] In internal combustion engines, oil separator systems to clean the blow-by gases from the crankcase are well known in the art. Similarly, impact separators are well known in the art to separate the oil mist from the blow-by gases by impact of the incoming blow-by gases on suitably designed structures. New and harder regulations for pollutant emission require innovative designs for the oil mist separator systems to comply with the stricter regulation regimes as well as improve the efficiency of the respective internal combustion engines.
[0004] In existing oil mist separators, improvement in the cleaning power is today required more than ever. While improving on the cleaning capacity and power, conflicting requirements have to be balanced to produce a product which

is both compliant to stricter regulations and is meeting operational requirements. Some conflicting requirements, for example, include longer maintenance free service life, as small as possible pressure loss, very compact design to produce compact engines, and a separation efficiency as high as possible to at least successfully meet the stringent regulations.
[0005] Conventionally, use of baffle plates to separate the oil from the blow-by gases are known in the art. Numerous designs have been proposed in which various arrangements of baffle plates have been propounded over time. Some baffle plates are arranged so as to focus on longer maintenance free service life, some are arranged to focus on increasing cleaning capacity, some are arranged to facilitate compact designs, some are only focused on balancing the pressure loss. But none of the prior arts have ever successfully met all the above criterias.
[0006] For example, DE102017120139A1 uses multiple baffle separators positioned in a straight line as a series, for increasing the cleaning efficiency while using pressure relief valves such that the pressure loss due to the baffle separators is balanced. The use of pressure relief valves achieves the balance of pressure loss but increases the manufacturing cost, the manufacturing complexity, and renders the oil mist separator unusable for compact designs. Similarly, DE10125404A1 uses baffle plates and uses their concave and convex side for separating and redirecting blow-by gases for increasing the cleaning efficiency. As the blow- by gases are redirected by the convex side of the baffles of the first separating lamellae at the inlet, they hit the concave sides of the baffles of the second lamellae and after again hitting the concave sides of the baffles of the first separating lamellae, they then flow through the gap between the baffles of the second separating lamellae. In this arrangement, the blow-by gases experience substantial pressure loss as they have to flow to the outlet through the gap between baffles. Further, the cleaning efficiency is only partially increased and the pressure loss proves to eliminate possibility of positioning

further separators positioned downstream thereto.
[0007] In light of the above shortcomings and drawbacks of the existing oil mist separators, there exists a need for an oil mist separator without any substantial pressure loss for allowing further separators downstream the initial separators. Further, there exists a need for an oil mist separator which is simple in design and compact so as to limit the manufacturing cost for achieving desired cleaning efficiency and acceptable for providing compact design for the internal combustion engines.
[0008] The present invention deals with a design of an improved oil mist pre-separator providing an improved and alternative embodiment ensuring simple and efficient design, lower manufacturing cost, and a possibility of using downstream separators enhancing overall cleaning efficiency. The present invention further provides an efficient and compact oil mist pre-separator.
SUMMARY
[0009] Embodiments of the present disclosure present technological improvements as solutions to one or more of the above-mentioned technical problems recognized by the inventor(s) in conventional systems.
[0010] In an aspect of the present disclosure, an oil mist pre-separator is provided. The oil mist pre-separator comprises a baffle arrangement, an inlet to introduce blow-by gases to the baffle arrangement, and an outlet to exit the blow-by gases from the baffle arrangement. The baffle arrangement comprises a first baffle plate, a second baffle plate, a third baffle plate, a fourth baffle plate, and a rectangular wall. The first baffle plate, the second baffle plate, and the third baffle plate have a circular arch shape. The first baffle plate is arranged at the bottom of the baffle arrangement. A concave side of the circular arch shape of the first baffle plate is arranged to face the incoming blow-by gases. A

concave side of the circular arch shape of the second baffle plate is arranged to face the re-directed incoming blow-by gases from the first baffle plate. A concave side of the circular arch shape of the third baffle plate is arranged to face the re-directed incoming blow-by gases from the second baffle plate. The fourth baffle plate has a flat rectangular shape and is arranged at the top of the baffle arrangement. The fourth baffle plate is arranged to face the re-directed incoming blow-by gases from the third baffle plate. The rectangular wall is placed adjoining the fourth baffle plate and faces convex sides of the first and third baffle plates.
[0011] The third baffle plate is arranged just above and adjoining the first baffle plate. The second baffle plate is arranged opposite to the first and the third baffle plates at a height from the first baffle plate such that the concave side of the second baffle plate faces the concave sides of both the first and third baffle plates. The fourth baffle plate is arranged above the first, the second, and the third baffle plates and is facing downwards. The incoming blow-by gases are lifted upwards against the gravity from the bottom to the top and towards the fourth baffle plate by the arrangement of the first, the second, and the third baffle plates, and wherein the rectangular wall redirects the blow-by gases downwards and to the outlet.
[0012] In another aspect of the present disclosure, an oil mist separator is provided. The oil mist separator comprises an oil mist pre-separator, an inlet to introduce blow-by gases to the oil mist pre-separator, a first impactor for separating oil from blow-by gases, a second impactor for separating oil from blow-by gases, and an outlet to facilitate exit of the cleaned blow-by gases. The first impactor is arranged downstream of the oil mist pre-separator. The second impactor is arranged downstream of the first impactor.
[0013] The oil mist pre-separator comprises a baffle arrangement. The baffle

arrangement comprises a first baffle plate, a second baffle plate, a third baffle plate, a fourth baffle plate, and a rectangular wall. The first baffle plate, the second baffle plate, and the third baffle plate have a circular arch shape. The first baffle plate is arranged at the bottom of the baffle arrangement. A concave side of the circular arch shape of the first baffle plate is arranged to face the incoming blow-by gases. A concave side of the circular arch shape of the second baffle plate is arranged to face the re-directed incoming blow-by gases from the first baffle plate. A concave side of the circular arch shape of the third baffle plate is arranged to face the re-directed incoming blow-by gases from the second baffle plate. The fourth baffle plate has a flat rectangular shape and is arranged at the top of the baffle arrangement. The fourth baffle plate is arranged to face the re-directed incoming blow-by gases from the third baffle plate. The rectangular wall is placed adjoining the fourth baffle plate and faces convex sides of the first and third baffle plates.
[0014] The third baffle plate is arranged just above and adjoining the first baffle plate. The second baffle plate is arranged opposite to the first and the third baffle plates at a height from the first baffle plate such that the concave side of the second baffle plate faces the concave sides of both the first and third baffle plates. The fourth baffle plate is arranged above the first, the second, and the third baffle plates and is facing downwards. The incoming blow-by gases are lifted upwards against the gravity from the bottom to the top and towards the fourth baffle plate by the arrangement of the first, the second, and the third baffle plates, and wherein the rectangular wall redirects the blow-by gases downwards and to the outlet.
[0015] Additional aspects, advantages, features and objects of the present disclosure would be made apparent from the drawings and the detailed description of the illustrative embodiments.

[0016] It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the below mentioned detailed description and drawings.
BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
[0017] The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, example constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers.
[0018] Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein:
Fig. 1 is a perspective view depicting a cylinder head cover, in accordance with an exemplary embodiment of the present disclosure;
Fig. 2 illustrates perspective view of an oil mist separator, in accordance with exemplary embodiments of the present disclosure; and
Fig. 3 is a front-sectional view of an oil mist pre-separator, in accordance with an exemplary embodiment of the present disclosure.

[0019] In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non- underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.
DETAILED DESCRIPTION
[0020] The following detailed description illustrates embodiments of the present disclosure and manners by which they can be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognize that other embodiments for carrying out or practicing the present disclosure are also possible. The person skilled in the art will recognize many variations, alternatives, and modifications of the embodiments of the present disclosure. It should be understood that this invention is not limited to the particular methodology, protocols, and the like, described herein and as such may vary. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention, which is defined solely by the claims.
[0021] Unless stated otherwise, or implicit from context, the following terms and phrases include the meanings provided below. Unless explicitly stated otherwise, or apparent from context, the terms and phrases below do not exclude the meaning that the term or phrase has acquired in the art to which it pertains. The definitions are provided to aid in describing particular embodiments of the aspects described herein, and are not intended to limit the claimed invention, because the scope of the invention is limited only by the claims. Further, unless otherwise required by context, singular terms shall

include pluralities and plural terms shall include the singular.
[0022] As used herein, the term “comprising” or “comprises” is used in reference to compositions, methods, and respective component(s) thereof, that are essential to the invention, yet open to the inclusion of unspecified elements, whether essential or not.
[0023] The singular terms “a”, “an”, and “the” include plural references unless the context clearly indicates otherwise. Similarly, the word “or” is intended to include “and” unless the context clearly indicates otherwise. Thus, for example, references to the “method” includes one or more methods, and/or steps of the type described herein, and/or which will become apparent to those persons skilled in the art upon reading this disclosure and so forth.
[0024] Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of this disclosure, suitable methods and materials are described below. The term “comprises” means “includes”. The abbreviation, “e.g.” is derived from the Latin exempli gratia and is used herein to indicate a non-limiting example. Thus, the abbreviation “e.g.” is synonymous with the term “for example”.
[0025] In an aspect of the present disclosure, an oil mist pre-separator is provided. The oil mist pre-separator comprises a baffle arrangement, an inlet to introduce blow-by gases to the baffle arrangement, and an outlet to exit the blow-by gases from the baffle arrangement. The baffle arrangement comprises a first baffle plate, a second baffle plate, a third baffle plate, a fourth baffle plate, and a rectangular wall. The first baffle plate, the second baffle plate, and the third baffle plate have a circular arch shape. The first baffle plate is arranged at the bottom of the baffle arrangement. A concave side of the circular arch shape of the first baffle plate is arranged to face the incoming blow-by gases. A

concave side of the circular arch shape of the second baffle plate is arranged to face the re-directed incoming blow-by gases from the first baffle plate. A concave side of the circular arch shape of the third baffle plate is arranged to face the re-directed incoming blow-by gases from the second baffle plate. The fourth baffle plate has a flat rectangular shape and is arranged at the top of the baffle arrangement. The fourth baffle plate is arranged to face the re-directed incoming blow-by gases from the third baffle plate. The rectangular wall is placed adjoining the fourth baffle plate and faces convex sides of the first and third baffle plates.
[0026] The third baffle plate is arranged just above and adjoining the first baffle plate. The second baffle plate is arranged opposite to the first and the third baffle plates at a height from the first baffle plate such that the concave side of the second baffle plate faces the concave sides of both the first and third baffle plates. The fourth baffle plate is arranged above the first, the second, and the third baffle plates and is facing downwards. The incoming blow-by gases are lifted upwards against the gravity from the bottom to the top and towards the fourth baffle plate by the arrangement of the first, the second, and the third baffle plates, and wherein the rectangular wall redirects the blow-by gases downwards and to the outlet.
[0027] According to another aspect of the present disclosure, an oil mist separator is provided. The oil mist separator comprises an oil mist pre-separator, an inlet to introduce blow-by gases to the oil mist pre-separator, a first impactor for separating oil from blow-by gases, a second impactor for separating oil from blow-by gases, and an outlet to facilitate exit of the cleaned blow-by gases. The first impactor is arranged downstream of the oil mist pre-separator. The second impactor is arranged downstream of the first impactor.
[0028] The oil mist pre-separator comprises a baffle arrangement. The baffle

arrangement comprises a first baffle plate, a second baffle plate, a third baffle plate, a fourth baffle plate, and a rectangular wall. The first baffle plate, the second baffle plate, and the third baffle plate have a circular arch shape. The first baffle plate is arranged at the bottom of the baffle arrangement. A concave side of the circular arch shape of the first baffle plate is arranged to face the incoming blow-by gases. A concave side of the circular arch shape of the second baffle plate is arranged to face the re-directed incoming blow-by gases from the first baffle plate. A concave side of the circular arch shape of the third baffle plate is arranged to face the re-directed incoming blow-by gases from the second baffle plate. The fourth baffle plate has a flat rectangular shape and is arranged at the top of the baffle arrangement. The fourth baffle plate is arranged to face the re-directed incoming blow-by gases from the third baffle plate. The rectangular wall is placed adjoining the fourth baffle plate and faces convex sides of the first and third baffle plates.
[0029] The third baffle plate is arranged just above and adjoining the first baffle plate. The second baffle plate is arranged opposite to the first and the third baffle plates at a height from the first baffle plate such that the concave side of the second baffle plate faces the concave sides of both the first and third baffle plates. The fourth baffle plate is arranged above the first, the second, and the third baffle plates and is facing downwards. The incoming blow-by gases are lifted upwards against the gravity from the bottom to the top and towards the fourth baffle plate by the arrangement of the first, the second, and the third baffle plates, and wherein the rectangular wall redirects the blow-by gases downwards and to the outlet.
[0030] Embodiments of the present disclosure substantially eliminate, or at least partially address, problems in the prior art, and assist the manufacturers, consumers, and suppliers of the oil mist separators.

[0031] Referring now to the drawings, Fig. 1 illustrates a cylinder head cover 100 in an assembled state, according to the present invention. The cylinder head cover 100 may include different functional elements molded into it, according to various embodiments of the present disclosure. As shown in Fig. 1, the cylinder head cover 100 includes multiple fastener arrangements 102 to fasten the cylinder head cover 100 to a cylinder head (not shown) of an internal combustion engine (not shown).
[0032] Fig. 1 is merely an example. A person skilled in the art will recognize many variations, alternatives, and modifications of the embodiments of the present disclosure.
[0033] Fig. 2 illustrates a perspective view depicting an oil mist separator 200 integrated inside the cylinder head cover 100 of Fig. 1. As illustrated in the view, the oil mist separator 200 includes an oil mist pre-separator 202, an inlet 204 to introduce blow-by gases to the oil mist pre-separator 202, a first impactor 206 for separating oil from blow-by gases, a second impactor 208 for separating oil from blow-by gases, and an outlet 210 to facilitate exit of the cleaned blow-by gases.
[0034] Again referring to Fig. 2, the first impactor 206 is arranged downstream of the oil mist pre-separator 202, according to embodiments of the present disclosure. In accordance with embodiments of the present disclosure, the second impactor 208 is arranged downstream of the first impactor 206. In various embodiments, the first impactor 206 and the second impactor 208 may include all types of oil impactors known in the art.

[0035] Fig. 2 is merely an example. A person skilled in the art will recognize many variations, alternatives, and modifications of the embodiments of the present disclosure.
[0036] Moving on to Fig. 3, the oil mist pre-separator 202 is depicted in a front-sectional view. As may be seen, the oil mist separator 202 includes a baffle arrangement 300, the inlet 204 to introduce blow-by gases to the baffle arrangement 300, and an outlet 302 to exit the blow-by gases from the baffle arrangement 300. In various embodiments of the present disclosure, the blow-by gases are sucked into the inlet 204 from a crankcase (not shown) of the internal combustion engine (not shown).
[0037] According to an embodiment of the present disclosure, the baffle arrangement 300 includes a first baffle plate 304, a second baffle plate 306, a third baffle plate 308, a fourth baffle plate 310, and a rectangular wall 312. As may be clearly seen in Fig. 3, the first baffle plate 304, the second baffle plate 306, and the third baffle plate 308 have a circular arch shape, in accordance with an embodiment of the present disclosure. According to an embodiment of the present disclosure, the circular arch shape of the first baffle plate 304 and the second baffle plate 306 is semi-circular. In an embodiment of the present disclosure, the circular arch shape of the third baffle plate 308 is quarter-circular.
[0038] Again referring to Fig. 3, the first baffle plate 304 is arranged at the bottom 314 of the baffle arrangement 300. In an embodiment, a concave side 316 of the circular arch shape of the first baffle plate 304 is arranged to face the incoming blow-by gases. A concave side 318 of the circular arch shape of the second baffle plate 306 is arranged to face the re-directed incoming blow-by gases from the first baffle plate 304, in accordance with an embodiment of the present disclosure. According to an embodiment of the present disclosure, a

concave side 320 of the circular arch shape of the third baffle plate 308 is arranged to face the re-directed incoming blow-by gases from the second baffle plate 306.
[0039] According to Fig. 3 and an embodiment of the present disclosure, the third baffle plate 308 is arranged just above and adjoining the first baffle plate 304. The second baffle plate 306 is arranged opposite to both the first baffle plate 304 and the third baffle plate 308 at a height 322 from the first baffle plate 304, in accordance with an embodiment of the present disclosure. The second baffle plate 306 is arranged such that its concave side 318 faces the concave sides (316 and 320 respectively) of both the first baffle plate 304 and the third baffle plate 308, according to an embodiment of the present disclosure.
[0040] Further referring to Fig. 3, the fourth baffle plate 310 has a flat rectangular shape and is arranged at the top 324 of the baffle arrangement 300, in accordance with an embodiment of the present disclosure. According to an embodiment of the present disclosure, the fourth baffle plate 310 is arranged to face the re-directed incoming blow-by gases from the third baffle plate 308. The fourth baffle plate 310 is arranged above the first baffle plate 304, the second baffle plate 306, and the third baffle plate 308, and is facing downwards, in accordance with an embodiment of the present disclosure. The rectangular wall 312 is placed adjoining the fourth baffle plate 310 and faces convex sides 326 of the first baffle plate 304 and third baffle plate 306, according to an embodiment of the present disclosure. According to an embodiment of the present disclosure, multiple oil-draining ribs 328 are provided on the first baffle plate 304, the second baffle plate 306, the third baffle plate 308, the fourth baffle plate 310, and the rectangular wall 312.
[0041] Again referring to Fig. 3, the incoming blow-by gases are lifted upwards against the gravity from the bottom 314 to the top 324 of the baffle arrangement

300, and towards the fourth baffle plate 310 by the arrangement of the first baffle plate 304, the second baffle plate 306, and the third baffle plates 308, in accordance with an embodiment of the present disclosure. Further, the rectangular wall 312 redirects the blow-by gases downwards and to the outlet 302, according to an embodiment of the present disclosure.
[0042] Fig. 3 is merely an example. A person skilled in the art will recognize many variations, alternatives, and modifications of the embodiments of the present disclosure.
[0043] Embodiments of the present disclosure can be used for various purposes, including, though not limited to, manufacturing and servicing of oil mist separators or cylinder head cover.
[0044] Modifications to various embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as “including”, “comprising”, “incorporating”. “consisting of”, “have”, “is” used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural.

WE CLAIM:
1. An oil mist pre-separator, the oil mist pre-separator comprising: a baffle arrangement;
an inlet to introduce blow-by gases to the baffle arrangement; and an outlet to exit the blow-by gases from the baffle arrangement;
characterized in that:
the baffle arrangement comprising:
a first baffle plate, the first baffle plate having a circular arch shape, a concave side of the circular arch shape arranged facing the incoming blow-by gases;
a second baffle plate, the second baffle plate having a circular arch shape, a concave side of the circular arch shape arranged facing blow-by gases redirected from the first baffle plate;
a third baffle plate, the third baffle plate having a circular arch shape, a concave side of the circular arch shape arranged facing the blow-by gases redirected from the second baffle plate;
a fourth baffle plate, the fourth baffle plate having a flat rectangular shape and arranged at the top, the flat rectangular shape arranged facing the blow-by gases redirected from the third baffle plate; and
a rectangular wall, the rectangular wall placed adjoining the fourth baffle plate and facing convex sides of the first and third baffle plates;
wherein, the third baffle plate is arranged just above and adjoining the first baffle plate, and wherein, the second baffle plate is arranged opposite to the first

and the third baffle plates at a height from the first baffle plate such that the concave side of the second baffle plate faces the concave sides of both the first and third baffle plates, and wherein the fourth baffle plate is arranged above the first, the second, and the third baffle plates and is facing downwards, and wherein the incoming blow-by gases are lifted upwards against the gravity from the bottom to the top and towards the fourth baffle plate by the arrangement of the first, the second, and the third baffle plates, and wherein the rectangular wall redirects the blow-by gases downwards and to the outlet.
2. The oil mist pre-separator as claimed in claim 1, wherein multiple oil-draining ribs are provided on the first baffle plate, the second baffle plate, the third baffle plate, the fourth baffle plate, and the rectangular wall.
3. The oil mist separator as claimed in claim 1, wherein the oil mist pre-separator is integrated inside a cylinder head cover.
4. An oil-mist separator, the oil mist separator
comprising: an oil mist pre-separator;
an inlet to introduce blow-by gases to the oil mist pre-separator;
a first impactor for separating oil from blow-by gases, the first impactor arranged downstream of the oil mist pre-separator;
a second impactor for separating oil from blow-by gases, the second impactor arranged downstream of the first impactor; and
an outlet to facilitate exit of the cleaned
blow-by gases; characterized in that:
the oil mist pre-separator
comprising: a baffle arrangement;

the baffle arrangement comprising:
a first baffle plate, the first baffle plate having a
circular arch shape, a concave side of the circular arch shape
arranged facing the incoming blow-by gases;
a second baffle plate, the second baffle plate having a
circular arch shape, a concave side of the circular arch shape
arranged facing the re-directed incoming blow-by gases from
the first baffle plate;
a third baffle plate, the third baffle plate having a
circular arch shape, a concave side of the circular arch shape
arranged facing the re- directed incoming blow-by gases
from the second baffle plate;
a fourth baffle plate, the fourth baffle plate having a
flat rectangular shape, the flat rectangular shape arranged
facing the re- directed incoming blow-by gases from the
third baffle plate; and
a rectangular wall, the rectangular wall placed adjoining the fourth baffle plate and facing convex sides of the first and third baffle plates;
wherein, the third baffle plate is arranged just above and adjoining the first baffle plate, and wherein, the second baffle plate is arranged opposite to the first and the third baffle plates at a height from the first baffle plate such that the concave side of the second baffle plate faces the concave sides of both the first and third baffle plates, and wherein the fourth baffle plate is arranged above the first, the second, and the third baffle plates and is facing downwards, and wherein the incoming blow-by gases are lifted upwards against the gravity towards the fourth baffle plate by the arrangement of the first, the second, and the third baffle plates, and wherein the

rectangular wall redirects the blow-by gases downwards and to the first impactor.
5. The oil mist separator as claimed in claim 4, wherein multiple oil-draining ribs are provided on the first baffle plate, the second baffle plate, the third baffle plate, the fourth baffle plate, and the rectangular wall.
6. The oil mist separator as claimed in claim 4, wherein the oil mist separator is integrated inside a cylinder head cover.