Apparatuses and methods for a closed crankcase ventilation system of an internal combustion engine

Abstract

Described herein are engine systems, closed crankcase ventilation systems, and hot filter assemblies that are configured to filter out contaminants from the closed crankcase ventilation system prior to being returned to an air intake of the engine system. In some examples, a closed crankcase ventilation system can include an engine comprising a crankcase, an oil separator coupled to the crankcase, and a hot filter assembly coupled to the oil separator and mounted to an exhaust manifold of the engine or a turbine housing of a turbocharger. The hot filter assembly comprises a housing defining a cavity, a gas inlet fluidly coupled between the oil separator and the cavity, a gas outlet fluidly coupled between the cavity and an air intake of the engine, and at least one baffle extending across the cavity and defining a first and second gas pathways on opposite sides of the baffle.

Description

CROSS REFERENCE

[0001] The present application claims the priority to and benefit of U.S. Application, No. 63 / 691,868, which was filed on September 6, 2024. The aforementioned patent application is hereby incorporated by reference in its entirety.FIELD

[0002] This disclosure generally relates to emission control systems for internal combustion engines, and more specifically to a closed crankcase ventilation system.BACKGROUND

[0003] A vehicle typically includes an internal combustion engine with a closed crankcase ventilation system that routes gases from the engine crankcase to an oil separator, which separates the oil from the gases. The remaining raw gases, which still contain small droplets of oil, soot, water, and / or other contaminants, can then be routed to the air inlet in front of the turbocharger. These small droplets can deposit on various engine components, including the turbocharger, charge air cooler, intake manifold, injectors, and intake valves. Such deposits can reduce engine performance, decrease fuel economy, shorten component life, and increase ownership costs.SUMMARY

[0004] Described herein are engine systems, crankcase ventilation systems, and hot filter assemblies (which, in some examples, can be referred to hot filter boxes) that are configured to filter out all or a substantial portion of contaminants from the crankcase ventilation system prior to being returned to an air intake of the engine system. In some examples, a hot filter assembly, or hot filter box, can be coupled to and / or integrated with the exhaust manifold of the engine or a turbine housing of a turbocharger of the engine system. Blow-by gases from the crankcase of the engine can be routed to an oil separator, and remaining gases can be routed from the oil separator to the hot filter assembly where all or a substantial portion of any remaining contaminants are burned and / or filtered out of the air. The cleaned and dried gases can then be routed to the air intake of the engine system. The hot filter assembly can be configured to passively burn and filter out all or a substantial portion of the remaining contaminants in the gases from the crankcase due to its positioning against the exhaust manifold or turbine housing. In this way, CO2, NOx, and particulate matter emissions emitted by the engine can be reduced. Further, the longevity of engine components can be increased due to fewer deposits thereon.

[0005] The foregoing and other objects, features, and advantages of the disclosed technology will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] FIG. 1 is a system diagram of an exemplary engine system comprising a hot filter assembly downstream of an oil separator in a closed crankcase ventilation system. FIG. 2 is a perspective view of an exemplary engine with a hot filter assembly mounted to an exhaust manifold of the engine. FIG. 3 is a perspective view of an exemplary turbocharger with a hot filter assembly mounted to a housing of a turbine of the turbocharger. FIG. 4 is a perspective view of an exemplary hot filter assembly comprising a cavity and at least one baffle disposed therein. FIG. 5 is a top view of the hot filter assembly of FIG. 4. FIG. 6 is a top view of the hot filter assembly of FIG. 4 with the cover removed. FIG. 7 depicts an exemplary hot filter assembly with a single baffle extending through a cavity of the hot filter assembly. FIG. 8 depicts an exemplary hot filter assembly with a plurality of longitudinally extending baffles spaced horizontally apart across a cavity of the hot filter assembly. FIG. 9 depicts an exemplary hot filter assembly with a plurality of horizontally extending baffles spaced longitudinally apart across a cavity of the hot filter assembly. FIG. 10 is a perspective view of the hot filter assembly of FIG. 4 with a wire mesh filter arranged in the cavity of the hot filter assembly. FIG. 11 is a perspective view of a portion of a wire mesh tube that can be used as a conduit in a closed crankcase ventilation system, such as the system shown in FIG. 1. FIG. 12 is a flow chart of a method of operating a turbocharger for an internal-combustion engine. FIG. 13 is a cross-sectional view of an exemplary turbocharger, including an abraded surface on the inlet of the turbocharger. DETAILED DESCRIPTION Explanation of Terms

[0007] For purposes of this description, certain aspects, advantages, and novel features of the embodiments of this disclosure are described herein. The disclosed methods, apparatus, and systems should not be construed as being limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub-combinations with one another. The methods, apparatus, and systems are not limited to any specific aspect or feature or combination thereof, nor do the disclosed embodiments require that any one or more specific advantages be present or problems be solved. The scope of this disclosure includes any features disclosed herein combined with any other features disclosed herein, unless physically impossible.

[0008] Although the operations of some of the disclosed embodiments are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description encompasses rearrangement, unless a particular ordering is required by specific language set forth below. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed methods can be used in conjunction with other methods.

[0009] As used in this disclosure and in the claims, the singular forms "a," "an," and "the" include the plural forms unless the context clearly dictates otherwise. Additionally, the term "includes" means "comprises." Further, the terms "coupled" and "associated" generally mean electrically, electromagnetically, and / or physically (e.g., mechanically or chemically) coupled or linked and does not exclude the presence of intermediate elements between the coupled or associated items absent specific contrary language.

[0010] In the description, certain terms may be used such as "forward," "front," "rear," "back," "up," "down," "upper," "lower," "horizontal," "vertical," "left," "right," "longitudinal," "lateral," and the like. These terms are used, where applicable, to provide some clarity of description when dealing with relative relationships. However, these terms are not intended to imply absolute relationships, positions, and / or orientations. For example, with respect to an object, an "upper" surface can become a "lower" surface by turning the object over. Nevertheless, it is still the same object.

[0011] Similar components in different embodiments are described in the specification and illustrated in the figures with similar reference numbers for improved understanding and readability. However, it should be understood that this numbering convention is merely for convenience and is not intended to limit and / or exclude any claim scope.

[0012] Although there are alternatives for various components, parameters, operating conditions, etc., set forth herein, that does not mean that those alternatives are necessarily equivalent and / or perform equally well. Nor does it mean that the alternatives are listed in a preferred order unless stated otherwise.Overview of the Disclosed Technology

[0013] As introduced above, internal combustion engines generate blow-by gases that escape from the combustion chamber and enter the crankcase. These blow-by gases can contain a mixture of oil, soot, water, and other contaminants. Managing these gases is necessary for maintaining engine performance and complying with stringent emission standards set by regulatory bodies.

[0014] Current systems for managing blow-by gases typically involve routing the gases from the crankcase to an oil separator. The oil separator separates the oil from the gases, but the remaining gases still contain small droplets of oil, soot, water, and other contaminants. These gases are then routed to the air inlet of the engine system (such as in front of the turbocharger). The small droplets in the gases can deposit on various engine components, such as the turbocharger, charge air cooler, intake manifold, injectors, and intake valves. These deposits can lead to reduced engine performance, decreased fuel economy, shortened component life, and increased ownership costs.

[0015] The disclosed systems and components address the issues associated with current blow-by gas management systems by introducing a hot filter assembly (as shown in FIGS. 4-6) coupled to (and in some instances, integrated into) the exhaust manifold (as shown in FIG. 2) or the turbine housing of the turbocharger (as shown in FIG. 3). The hot filter assembly can comprise a body made of metal (e.g., cast iron) and at least one baffle plate (as shown in FIGS. 4-10). In some examples, the hot filter assembly can comprise a wire mesh filter arranged inside the body (as shown in FIG. 10).

[0016] An engine system including the hot filter assembly, such as the system shown in FIG. 1, can route blow-by gases from the crankcase to an oil separator, which separates most or at least a portion of the oil from the gases. The remaining gases are then routed to the hot filter assembly, where heat transferred directly from the exhaust manifold or turbine housing to the body of the hot filter assembly burns the oil droplets and evaporates the water from the gases passing therethrough, thereby ensuring that only substantially cleaned and dried gases reach the air inlet of the engine system (which may be upstream of the turbocharger in some examples, and, in some cases, wherein such gases may form an abradable surface on the inlet of the turbocharger as described below in more detail). As a result, engine CO2, NOx, and particulate matter emissions are reduced, thereby contributing to better emission control and compliance with regulatory standards.Examples of the Disclosed Technology

[0017] FIG. 1 is a schematic diagram of an exemplary engine system 100 comprising a closed crankcase ventilation system 130 including a hot filter assembly 120, as described further below. Herein, the hot filter assembly 120 can also be referred to as a hot filter box 120. However, it should be noted that the hot filter assembly or box 120 need not be shaped as a box (e.g., it could instead have an oblong, hexagonal, or spherical shape). As described further below, the hot filter assembly or box 120 can be a component defining an internal cavity that is enclosed therein apart from a gas inlet and gas outlet of the hot filter assembly or box 120.

[0018] The engine system 100 comprises an engine 102, the engine 102 comprising an engine block 104, a crankcase 106, and an oil pan 108. The engine block 104 houses the cylinders of the engine and the crankcase 106 houses the crankshaft of the engine 102.

[0019] The engine 102 can comprise any internal combustion engine, such as a diesel engine, a gasoline engine, or a hydrogen internal combustion engine.

[0020] The engine block 104 can comprise an intake manifold 110 that directs intake air into cylinders in the engine block 104 and an exhaust manifold 112 that directs burned exhaust gases from the cylinders to an exhaust system of the engine system 100, which may include a turbine 116 of a turbocharger 114.

[0021] In some examples, as shown in FIG. 1 (and FIG. 2, as described further below), a hot filter box 120 can be mounted to and / or integrated with the exhaust manifold 112 of the engine 102.

[0022] As used herein, "mounted to" can refer to a first component being coupled to and placed in direct or indirect contact with a second component. For example, the first component can be directly coupled to the second component (without any intervening components therebetween) or indirectly coupled to the second component (such as via a mounting plate).

[0023] In some examples, the hot filter box 120 can be directly coupled to the exhaust manifold 112 of the engine 102 (for example, via bolts or other fasteners).

[0024] Alternatively, in some examples (as shown in FIG. 3), the hot filter box 120 (or another, similar hot filter box) can be mounted to and / or integrated with the housing of the turbine 116.

[0025] In some examples, the hot filter box 120 can be directly coupled to the housing of the turbine 116 (for example, via bolts or other fasteners).

[0026] During operation of the engine system 100, fresh air 122 from outside the engine system 100 can be pulled into an air filter 124. The air filter 124 can be configured to filter soot and ashes from the air passing therethrough.

[0027] The filtered intake air can be routed through a compressor 118 of the turbocharger 114 and routed toward the engine 102.

[0028] In some examples, as shown in FIG. 1, the compressed intake air is routed through a charge air cooler (CAC) 126 prior to entering the engine 102.

[0029] The compressed and cooled intake air is then routed into the intake manifold 110 of the engine 102 and into the cylinders inside the engine block 104, where it is used for combustion.

[0030] Combustion gases expelled from the cylinders are directed out of the engine 102 by the exhaust manifold 112. The combustion gases can then be routed through the turbine 116 and out an exhaust system 128.

[0031] The engine system 100 comprises a closed crankcase ventilation system 130 that takes blow-by gases from the crankcase 106 and routes them to an oil separator 132 via a first conduit 134. The oil separator 132 is configured to separate oil from the gases and return the separated oil to an oil pan 108 of the engine 102, via a second conduit 136.

[0032] In some examples, the first conduit 134 can be a wire mesh tube, such as the wire mesh tube 200 shown in FIG. 11.

[0033] As shown in FIG. 11, the wire mesh tube 200 can comprise an outer tubing layer 202 (e.g., comprising a polymer or metal) and an inner mesh layer 204 disposed around an inner surface of the outer tubing layer 202. A portion of the outer tubing layer 202 is dissected back from the inner mesh layer 204 in FIG. 11, for the purpose of illustration alone (so the underlying mesh layer 204 can be more easily visualized). The wire mesh tube 200 can have various diameters and lengths for different conduits of the engine system, as described further below.

[0034] Returning to FIG. 1, when the first conduit 134 comprises a wire mesh tube, such as the wire mesh tube 200, an inner diameter of the tube can be in a range of 20-30 mm (or about 25 mm) and a length of the tube can be in arrange of 220-275 mm (or about 250 mm). By using the wire mesh tube 200 as the first conduit 134 in the engine system 100, a temperature of the blow-by gases can be reduced by 5-7 degrees before reaching the oil separator 132. As a result, the efficiency of the oil separator 132 may be increased, thereby allowing a larger amount of oil to be separated from the gases.

[0035] In some examples, the oil separator 132 can separate about 80-90% of the oil out of the blow-by gases.

[0036] From the oil separator 132, the remaining gases are routed to the hot filter box 120 via a third conduit 138.

[0037] In some examples, the third conduit 138 can be a wire mesh tube, such as the wire mesh tube 200 shown in FIG. 11. In such examples, an inner diameter of the tube can be in a range of 20-30 mm (or about 25 mm) and a length of the tube can be in arrange of 450-550 mm (or about 500 mm). By using the wire mesh tube 200 as the third conduit 138 in the engine system 100, a droplet size oil droplets in the blow-by gases can be increased (e.g., to about 0.01 mm) and a temperature of the blow-by gases can be reduced by about 7 degrees before reaching the hot filter box 120. As a result, the efficiency of the hot filter box 120 may be increased, thereby allowing a larger amount of oil or other contaminants to be separated from the gases.

[0038] In some examples, the wire mesh tube of the third conduit 138 may comprise a slop, to enable draining of the oil back into the oil separator 132. The larger oil droplets (0.010mm) are more easily separated than the smaller droplets (0.001mm) . Conduit 138 helps to reduce the blow-by temperature by about 7 degrees, which results in an increase in size of the droplets. The larger droplets may drain back into the oil separator and the substantially all of the rest are burned in the hot filter box.

[0039] The hot filter box 120 is configured to burn the oil droplets and evaporate water in the remaining gases, thereby cleaning and drying the gases before returning them to the air intake (such as the air filter 124, upstream of the compressor 118) via a fourth conduit 140. More details of the hot filter box 120 are described below with reference to FIGS. 4-10.

[0040] In some examples, a first pressure sensor 142 and a second pressure sensor 144 are arranged on either side of the hot filter box 120 to monitor pressure of the blow-by gases and crankcase pressure.

[0041] For example, as shown in FIG. 1, the first pressure sensor 142 can be arranged in the third conduit 138 or attached to an inlet of hot filter box 120. As such, a pressure of gases entering the hot filter box 120 can be measured. This pressure may be indicative of the pressure of the crankcase 106 (which can be referred to as crankcase pressure).

[0042] The second pressure sensor 144 can be arranged in the fourth conduit 140 or attached to an outlet of the hot filter box 120. As such, a pressure of filtered gases exiting the hot filter box 120 can be measured.

[0043] In some examples, it may be desirable to maintain the crankcase pressure below zero KPa. If an output of the first pressure sensor 142 and / or second pressure sensor 144 indicates that crankcase pressure is above zero, an engine control system (i.e., controller) may send a signal to an indicator (e.g., an indicator light or audible indicator), and / or the engine control system may adjust engine operation to decrease the crankcase pressure below zero.

[0044] Further, leaks in the closed crankcase ventilation system 130 may be detectable by the outputs of the first pressure sensor 142 and the second pressure sensor 144. If the outputs of the first pressure sensor 142 and / or second pressure sensor 144 indicates that there is a leak, the engine control system may send a signal to an indicator of the engine or vehicle system.

[0045] As introduced above with reference to FIG. 1 and shown in FIG. 2, in some examples, the hot filter box 120 is attached to the exhaust manifold 112 of the engine 102. For example, the hot filter box 120 can be mounted to an outer surface of the exhaust manifold 112 such that a body or housing of the hot filter box 120 is positioned against and in face-to-face contact with at least a portion of the outer surface of the exhaust manifold 112.

[0046] In some examples, the body of the hot filter box 120 and the exhaust manifold 112 can be integrated together as one piece (e.g., molded or formed together as one piece of metal with walls separating the gas pathways in the exhaust manifold and hot filter box). Further, the exhaust manifold supplier molds the part as shown in Fig 4-6. The cover for the hot filter box 120 is welded after the wire mesh is install.

[0047] As such, heat from the hot exhaust gases flowing through the exhaust manifold 112 is transferred via the metal housing of the exhaust manifold to the metal body housing of the hot filter box 120 and the gases flowing therethrough.

[0048] In alternate examples, as shown in FIG. 3, the hot filter box 120 can be attached to or integrated with the housing 115 of the turbine 116. For example, the hot filter box 120 can be mounted to an outer surface of a side of the housing 115 of the turbine 116. As a result, heat from the hot exhaust gases flowing through the turbine 116 are transferred via the metal housing 115 of the turbine 116 to the metal body of the hot filter box 120 and the gases flowing through the interior of the hot filter box 120.

[0049] It should be noted that the hot filter box 120 in FIG. 3 is depicted schematically and shows two baffles instead of the one shown in FIG. 4-6 (as described below). As described herein, various numbers and arrangements of baffles are possible within the hot filter box 120.

[0050] In some examples, the body of the hot filter box 120 and the housing 115 of the turbine 116 can be integrated together (e.g., molded or formed together as one piece of metal with walls separating the gas pathways).

[0051] FIGS. 4-6 show different views of an example of the hot filter box 120.

[0052] The hot filter box 120 can comprise a body 146 and one or more conduits (or pipes or tubes) extending outward from openings in an outer housing 148 of the body 146. For example, the hot filter box 120 can comprise a first conduit 150 extending from a first opening 154 in the housing 148 and a second conduit 152 extending from a second opening 156 in the housing 148.

[0053] In some examples, the first conduit 150 and second conduit 152 can be elbows or short conduits or pipe fittings that are configured to couple to conduits in the engine system (e.g., the third conduit 138 and the fourth conduit 140 shown in FIGS. 1 and 2).

[0054] In some examples, the first conduit 150 and the second conduit 152 are integrated with the housing 148 (as shown in FIG. 10) and the entire hot filter box 120 is formed as one piece. As such, the hot filter box 120 is a closed system without access to an interior of the hot filter box 120.

[0055] In some examples, the first conduit 150 and second conduit 152 are directly coupled to the first opening 154 and the second opening 156, respectively, in the housing 148.

[0056] In some examples, the second conduit 152 is coupled to a second conduit fitting 160 that is integrated with the housing 148, around the second opening 156. As such, the second conduit 152 can be press fit into the second conduit fitting 160.

[0057] In some examples, as shown in FIGS. 4-6, the body 146 of the hot filter box 120 is a two-piece body (e.g., a two-piece casting) comprising the housing 148 and a cover 162 that is coupled to edges 164 around a perimeter of the housing 148 that defines an opening into the interior cavity of the housing 148.

[0058] The first conduit 150 can be coupled to a first conduit fitting 158 that is integrated with (i.e., molded or formed as one piece) the cover 162, around the first opening 154 that extends through the cover 162. As such, the first conduit 150 (or elbow) can be press fit into the first conduit fitting 158 (as shown in FIGS. 4 and 5)

[0059] The cover 162 can be removably coupled to the housing 148 via fasteners (e.g., bolts). FIGS. 4 and 5 show perspective and top views, respectively, show the cover 162 coupled to the housing 148, and FIG. 6 is a top view of the hot filter box 120 with the cover 162 removed. The edges 164 of the housing 148 can comprises one or more apertures 166 that correspond to apertures 168 in the cover 162 and are configured to receive fasteners therethrough to couple the cover 162 to the housing 148.

[0060] In some examples, at least a central portion of the cover 162 is transparent or semitransparent such that the interior cavity 170 of the housing 148 can be at least partially visualized from outside the hot filter box 120.

[0061] In some examples, the cover 162 is fixed to the housing 148 (e.g., via welding) such that it cannot be removed from the housing 148.

[0062] The cavity 170 is defined by a first interior sidewall 176, a second interior sidewall 177, a third interior sidewall 178, a fourth interior sidewall 179, and a rear interior wall 180 of the housing 148 (as shown in FIG. 6). The edges 164 are edges of the first, second, third, and fourth interior sidewalls 176-179.

[0063] In some examples, the cavity 170 has a volume in a range of 250,000-350,000 mm 3< or of 300,000 mm 3< . The volume of the cavity 170 can be changed depending on the engine size, and thus the expected volume of blow-by gases.

[0064] The body 146 comprises one or more baffles 172 (which can also be referred to as baffle plates) disposed inside the cavity 170. The one or more baffles 172 are configured to direct gas flow, or gases 174, through the cavity 170, as depicted in FIG. 6, and reduce the velocity of the blow-by gases. As a result, the gases can increase in temperature as they travel through the cavity 170 and oil and / or other contaminants can be burned out of the gases. The longer the flow path for the gases 174 inside the cavity 170 (which results from the baffle 172 or baffles extending across a majority of the length or width of the cavity 170), the greater increase in temperature that the gases 174 experience.

[0065] The one or more baffles 172 can extend from the rear interior wall 180 toward a front interior wall of the housing 148 (when formed as a one-piece body construction) or an interior surface of the cover 162 (when present, in a two-piece construction, as shown in FIGS. 4-6).

[0066] In some examples, the one or more baffles 172 are connected between the rear interior wall 180 and the front interior wall or the cover 162.

[0067] In some examples, an interior surface of the cover 162 defines the front interior wall.

[0068] The rear interior wall 180 (which can also be referred to as a bottom wall) is arranged opposite the cover 162 or front interior wall across the cavity 170.

[0069] As shown in FIGS. 4-6, the hot filter box 120 comprises a single baffle 172 that extends from the rear interior wall 180 to a level flush with the edges 164. The single baffle 172 further extends from the first interior sidewall 176 toward the second interior sidewall 177 (in a horizontal direction 195) and then curves to extend through a central portion of the cavity 170 toward the fourth interior sidewall 179 (in a longitudinal direction 196). A free end 182 of the baffle 172 is spaced away from the fourth interior sidewall 179. An attached end 184 of the baffle 172 can be spaced away from the third interior sidewall 178.

[0070] As such, in the example of the hot filter box 120 shown in FIGS. 4-6, blow-by gases 174 from the oil separator can enter the hot filter box 120 through the first opening 154 and then travel through the cavity 170, along a first side 171 of the baffle 172 (and the second interior sidewall 177) toward the fourth interior sidewall 179, around the free end 182 of the baffle 172 and along the fourth interior sidewall 179, and along a second side 173 of the baffle 172 (and the first interior sidewall 176), and out the second opening 156. The remaining gases can then flow to an intake system of the engine, as described above.

[0071] In this way, the baffle 172 can define a first gas pathway between the first side 171 of the baffle 172 and the second interior sidewall 177 (or along the first side 171) and a second gas pathway between the second side 173 of the baffle 172 and the first interior sidewall 176 (or along the second side 173).

[0072] As such, the gases 174 can flow in a first direction through the first gas pathway and in a second direction through the second gas pathway, the first direction opposite the second direction.

[0073] In some examples, the baffle 172 can comprise two attached ends instead of the attached end 184 and the free end 182. For example, in some instances, the baffle 172 can be attached to both the first interior sidewall 176 and the fourth interior sidewall 179. In such instances, an end portion of the baffle 172 that is coupled to the fourth interior sidewall 170 can include one or more apertures or slots, or one or more elongated slots, that enable gas to pass therethrough, from the first gas pathway to the second gas pathway.

[0074] The rear interior wall 180 can be opposite (across a wall of the housing 148) a rear exterior wall 186 of the housing 148 (shown in FIG. 4). In some examples, the rear exterior wall 186 can be coupled to and / or positioned against the exhaust manifold or the turbine housing, as described above with reference to FIGS. 1-3.

[0075] For example, in some instances, the hot filter box 120 can comprise one or more mounting flanges 188 configured to fasten to an outer wall of the exhaust manifold or turbine housing. Alternatively the hot filter box may be welded to the exhaust manifold and the turbine housing of the turbocharger 114, or it may be cast as one piece with the exhaust manifold but with two separate cavities one for exhaust gases and one cavity for blow-by gases. Finally it may be bolted to the exhaust manifold.

[0076] In some examples, the housing 148 of the hot filter box 120 can comprise a metal that is heat resistant, such as cast iron.

[0077] In some examples, a thickness of the walls of the housing 148 can be in a range of 7-9 mm.

[0078] Due to its placement against the hot exhaust manifold or turbine housing, blow-by gases 174 traveling through the cavity 170 of the hot filter box 120 can increase in temperature by about 400 °C. In some examples, the temperature increase of the blow-by gases entering vs. exiting the hot filter box 120 can be in a range of 350-450 °C.

[0079] In some examples, the hot filter box can comprise a coupling 190 that is configured to couple to another component of the engine, thereby fixing the hot filter box 120 to the engine. The coupling 190 is used to connect the rear exhaust manifold to the central piece exhaust manifold. This coupling cannot be used for hot filter box attachment.

[0080] In some examples, a filter element 192 can be arranged within the cavity 170 (as shown in FIG. 10). In some examples, as shown in FIG. 10, the filter element 192 is arranged within the cavity 170, on both sides of the baffle 172.

[0081] In some examples, the filter element 192 is one piece that curves around the baffle 172.

[0082] In some examples, the filter element 192 comprises two or more separate pieces arranged within the cavity 170.

[0083] In some examples, the filter element 192 is a metal mesh screen (which can also be referred to as a wire mesh or wire mesh filter) that is configured to capture small oil droplets or other contaminants inside the hot filter box 120 such that only clean air is released from the hot filter box 120. The metal mesh screen can be temperature resistant, such that it will not melt at temperatures below 700 °C.

[0084] FIGS. 7-9 depict alternative baffle arrangements for a hot filter box, such as the hot filter box 120 of FIGS. 4-6. For example, the hot filter box 120 can be modified to include any of the baffle arrangements shown in FIGS. 7-9.

[0085] FIG. 7 depicts a first baffle arrangement that is similar to the baffle arrangement shown in FIGS. 4-6, except the inflow opening and outflow opening are arranged on opposite sides of the baffle 172 than in FIGS. 4-6. For example, as shown in FIG. 7, blow-by gases from the oil separator flow in through the second opening 156, along the second side 173 of the baffle 172, around the free end 182 of the baffle 172, along the first side 171 of the baffle 172, and out the first opening 154.

[0086] FIG. 8 depicts a second baffle arrangement for a hot filter box. The hot filter box shown in FIG. 8 comprises a housing 300 with an interior cavity 302 that is defined by a first interior sidewall 304, a second interior sidewall 306, a third interior sidewall 308, a fourth interior sidewall 310, and a rear interior wall (the bottom of the housing 300 in the view of FIG. 8).

[0087] As noted above, the housing 148 of the hot filter box 120 of FIGS. 4-6 can be modified to include the baffle arrangement of FIG. 8. For example, the first, second, third, and fourth interior sidewalls 304, 306, 308, and 310 can correspond to the first, second, third, and fourth interior sidewalls 176-179 of the housing 148.

[0088] The housing 300 comprises three baffles extending longitudinally across the cavity 302, with respect to the longitudinal direction 196.

[0089] For example, the three baffles include a first baffle 312 extending from the third interior sidewall 308 toward (but spaced away from) the fourth interior sidewall 310 (in the longitudinal direction 196), a second baffle 314 extending from the fourth interior sidewall 310 toward (but spaced away from) the third interior sidewall 308 (in the longitudinal direction), and third baffle 316 extending from the third interior sidewall 308 toward (but spaced away from) the fourth interior sidewall 310 (in the longitudinal direction 196). The first, second, and third baffles 312, 314, and 316 are spaced apart from each other in the horizontal direction 195.

[0090] In this way, adjacent baffles extend from opposite sidewalls of the housing 300 in an alternating manner or arrangement.

[0091] The housing 300 comprises a first opening 318 and a second opening 320 for blow-by or cleaned gases. In some examples, the first opening 318 is an inlet opening that receives blow-by gases from the oil separator and the second opening 320 is an outlet opening that expels cleaned (or filtered) gases after passing through the hot filter box. An exemplary flow path for the gases through the housing 300 for this inlet / outlet arrangement is shown by arrows 322 in FIG. 8.

[0092] In some examples, the second opening 320 is an inlet opening that receives blow-by gases from the oil separator and the first opening 318 is an outlet opening that expels cleaned (or filtered) gases after passing through the hot filter box. The flow path for the gases through the housing in this alternate inlet / outlet arrangement would be opposite the arrows 322 shown in FIG. 8.

[0093] In alternative examples, the first and third baffles 312 and 316 can instead extend from the fourth interior sidewall 310 and the second baffle 314 can extend from the third interior sidewall 308.

[0094] In some examples, the housing 300 can comprise more or less than three baffles that alternate which opposing walls they extend from (in the longitudinal direction, as shown in FIG. 8). For example, the housing can comprise two longitudinally extending baffles that extend from opposing interior sidewalls (e.g., third and fourth interior sidewalls 308 and 310), four longitudinally extending baffles that extend from opposing interior sidewalls in the alternating manner, or the like.

[0095] In some examples, as depicted in FIG. 9, instead of extending in the longitudinal direction 196, the baffles can extend in the horizontal direction. Specifically, in FIG. 9, a hot filter box housing 400 can have an interior cavity 402 that is defined by a first interior sidewall 404, a second interior sidewall 406, a third interior sidewall 408, a fourth interior sidewall 410, and a rear interior wall (the bottom of the housing 400 in the view of FIG. 9).

[0096] As noted above, the housing 148 of the hot filter box 120 of FIGS. 4-6 can be modified to include the baffle arrangement of FIG. 8. For example, the first, second, third, and fourth interior sidewalls 404, 406, 408, and 410 can correspond to the first, second, third, and fourth interior sidewalls 176-179 of the housing 148.

[0097] The housing 400 comprises six baffles extending horizontally across the cavity 402, with respect to the horizontal direction 195.

[0098] For example, the six baffles include a first set of baffles 412, each extending from the second interior sidewall 406 toward (but spaced away from) the first interior sidewall 404, and a second set of baffles 414, each extending from the first interior sidewall 404 toward (but spaced away from) the second interior sidewall 306.

[0099] All the baffles in the first set of baffles 412 and the second set of baffles 414 are spaced apart from one another in the longitudinal direction 196. The first set of baffles 412 and the second set of baffles 414 alternate with each other across the cavity 402 such that each baffle of the first set of baffles 412 is arranged between two adjacent baffles of the second set of baffles 414.

[0100] In this way, adjacent baffles extend from opposite sidewalls of the housing 400 in an alternating manner. This allows gases to follow a serpentine path through the cavity 402. By having more baffles, the time for the gases to flow through the cavity 402 may increase and / or a contact surface are of the gases against the heated baffles increases, thereby increasing the heat of the gases flowing therethrough and burning off more oil and / or contaminants.

[0101] The housing 400 comprises a first opening 418 and a second opening 420 for blow-by or cleaned gases. In some examples, the first opening 418 is an inlet opening that receives blow-by gases from the oil separator and the second opening 420 is an outlet opening that expels cleaned (or filtered) gases after passing through the hot filter box. An exemplary flow path for the gases through the housing 400 for this inlet / outlet arrangement is shown by arrows 422 in FIG. 9.

[0102] In some examples, the second opening 420 is an inlet opening that receives blow-by gases from the oil separator and the first opening 418 is an outlet opening that expels cleaned (or filtered) gases after passing through the hot filter box. The flow path for the gases through the housing in this alternate inlet / outlet arrangement would be opposite the arrows 422 shown in FIG. 9.

[0103] In alternative examples, the first set of baffles 412 can instead extend from the first interior sidewall 304 and the second set of baffles 414 can extend from the second interior sidewall 306.

[0104] In some examples, the housing 400 can comprise more or less than six baffles that alternate which opposing walls they extend from (in the horizontal direction, as shown in FIG. 9). For example, the housing 400 can comprise two, three, four, fix, seven, or the like, horizontally extending baffles that extend from opposing interior sidewalls (e.g., first and second interior sidewalls 404 and 406).

[0105] As noted above, any of the baffles described herein can comprise two attached ends instead of one attached end and one free end. For example, in some instances, the one or more baffles of a hot filter assembly can be attached between two interior sidewalls of the hot filter assembly and an end portion of the baffle can include one or more apertures or slots, or one or more elongated slots, that enable gas to pass therethrough, from the first gas pathway to the second gas pathway that are defined by the baffle.

[0106] In this way, a hot filter box mounted to or integrated with an exhaust manifold of an engine, or a turbine housing can be configured to passively heat blow-by gases passing therethrough, thereby burning remining oil from the gases and filtering out contaminants that remain after an oil separator. As a result, substantially clean and dry air can be returned to an air inlet of an engine system, such as upstream of a compressor. As a result, engine CO2, NOx, and particulate matter emissions are reduced, thereby contributing to better emission control and compliance with regulatory standards.

[0107] Referring to Figs. 12 and 13, in an alternative or additional aspect, the present disclosure includes a method 1200 of operating a turbocharger 114 in an engine system 100 including an internal-combustion engine wherein a hot filter assembly 120 is configured to receive crankcase gases and output remaining gases carrying particulate matter and used to form an abradable surface 119 on the turbocharger inlet 117 that improves an efficiency of air flow into the turbocharger 114.

[0108] At step 1201, method 1200 includes routing gases that emanate from a crankcase of the engine through an oil separator and a hot filter assembly, wherein the hot filter assembly is configured to output remaining gases including particulate matter. For example, in an aspect and additionally referring back to Fig. 1, blow-by gases and oil from the crankcase 106 are routed via first conduit 134 through oil separator 132 and then via second conduit 138 through hot filter assembly 120, which removes a substantial portion of the oil and other contaminants from the gases. Yet, the hot filter assembly 120 is configured to output remaining gases having particulate matter, such as but not limited to soot. In some aspects, the hot filter assembly 120 is configured to output the remaining gases including particulate matter with a size of 1 micron or less. In some cases, the particulate matter is soot and / or other by-products of the combustion process of the engine.

[0109] At step 1202, method 1200 includes directing the remaining gases from the hot filter assembly to a turbocharger. For example, in an aspect and additionally referring back to Figs. 1 and 3, the remaining gases that include the particular matter are directed via fourth conduit 140 to the turbocharger 114. In some aspects, the remaining gases are directed to an inlet of the turbocharger 114, such as the turbocharger inlet 118 to the compressor 118. In some optional aspects, before reaching the turbocharger 114, the remaining gases are directed through an air filter 124 (Fig. 1) and are mixed with fresh air 122 and the resulting mixture is directed to the turbocharger inlet 118 to the compressor 118. In some cases, the fresh air 122 may include have a moisture level higher than the moisture level of the remaining gases that our output by the hot filter assembly 120.

[0110] At step 1203, method 1200 includes forming, via the particulate matter in the remaining gases, an abradable layer on at least a portion of an inlet surface of the turbocharger. For example, in an aspect, the remaining gases with the particulate matter contact a portion of the surface of the turbocharger inlet 118 to the compressor 118 and form an abradable layer 119 on at least a portion of the surface of the turbocharger inlet 118. For instance, the abradable layer 119 is formed between a portion of the surface of the turbocharger inlet 118 and a distal end of one or more blades 123 of a compressor wheel 125 of the compressor 118. The one or more blades 123 includes one or more full blades, and / or one or more splitter blades. The abradable layer 119 is formed of at least the particulate matter, and / or a mixture of the particulate matter and moisture, existing in the remaining gases and / or from the fresh air 122, condensed on the surface of the turbocharger inlet 118.

[0111] At step 1204, method 1200 includes abrading, via one or more blades of a compressor of the turbocharger, the abradable layer to form an abraded surface layer between the inlet surface and the one or more blades. For example, in an aspect, the one or more blades 123 of the compressor wheel 125 of the compressor 118 of the turbocharger 114 rotate and cut into, rub, or otherwise wear away a portion of the abraded layer formed by deposition of the particulate matter on the portion of the surface of the turbocharger inlet 118. Consequently, a gap between the surface of the turbocharger inlet 118 and the distal end of the one or more blades 123 is reduced, thereby reducing leakage of the incoming airflow around the one or more blades 123 and improving the efficiency of the compressor 118 and hence the turbocharger 114.

[0112] The process is cyclically repeated by operation of the engine system 100, ensuring that the abradable surface 119 at the turbocharger inlet 117 is continually renewed and abraded, which may enhance performance and / or longevity of the turbocharger 114.Additional Examples of the Disclosed Technology

[0113] In view of the above-described implementations of the disclosed subject matter, this application discloses the additional examples enumerated below. It should be noted that one feature of an example in isolation or more than one feature of the example taken in combination and, optionally, in combination with one or more features of one or more further examples are further examples also falling within the disclosure of this application.

[0114] The features described herein with regard to any example can be combined with other features described in any one or more of the other examples, unless otherwise stated. For example, any one or more features of one vehicle can be combined with any one or more features of another vehicle. As another example, any one or more features of one splash shield assembly can be combined with any one or more features of another splash shield assembly.

[0115] Clause 1. A closed crankcase ventilation system, comprising: an engine comprising a crankcase; an oil separator coupled to the crankcase and configured to separate oil from blow-by gases received from the crankcase; and a hot filter assembly coupled to the oil separator and mounted to an exhaust manifold of the engine or a turbine housing of a turbocharger, the hot filter assembly comprising: a housing defining an interior cavity of the hot filter assembly; a gas inlet fluidly coupled between the oil separator and the interior cavity; a gas outlet fluidly coupled between the interior cavity and an air intake of the engine; and at least one baffle that extends across the interior cavity and defines a first gas pathway along a first side of the at least one baffle and a second gas pathway along a second side of the at least one baffle, wherein gases flow through the first gas pathway in a first direction and gases flow through the second gas pathway in a second direction that is opposite the first gas pathway.

[0116] Clause 2. The closed crankcase ventilation system of clause 1, further comprising a first pressure sensor at or upstream of the gas inlet of the hot filter assembly, and a second pressure sensor at or downstream of the gas outlet of the hot filter assembly.

[0117] Clause 3. The closed crankcase ventilation system of clause 1, wherein the housing of the hot filter assembly is coupled directly to an outer surface of the exhaust manifold of the engine such that heat from hot exhaust gases traveling through the exhaust manifold transfers across walls of the housing to gases flowing through the interior cavity of the hot filter assembly.

[0118] Clause 4. The closed crankcase ventilation system of clause 1, further comprising a wire mesh filter arranged inside the interior cavity.

[0119] Clause 5. The closed crankcase ventilation system of clause 1, wherein the at least one baffle includes two or more baffles spaced apart from one another and extending from opposite sidewalls of the housing in an alternating arrangement.

[0120] Clause 6. The closed crankcase ventilation system of clause 1, wherein the at least one baffle extends between a rear interior wall and a front interior wall of the housing and further extends from a first interior sidewall toward a second interior sidewall of the housing, wherein the first and second interior sidewalls extend between the rear and front interior walls.

[0121] Clause 7. The closed crankcase ventilation system of clause 1, wherein the at least one baffle extends across a majority of the interior cavity in either a longitudinal direction or a horizontal direction.

[0122] Clause 8. A hot filter assembly for an engine system, comprising: a metal housing comprising interior walls that define an interior cavity of the hot filter assembly, the interior walls comprising at least a rear interior wall, a first interior sidewall, and a second interior sidewall, and wherein the interior cavity is further defined by a front interior wall of the hot filter assembly; a first opening in communication with the interior cavity; a second opening in communication with the interior cavity; and at least one baffle arranged inside the interior cavity and extending from the rear interior wall to the front interior wall of the hot filter assembly, wherein the at least one baffle has an attached end attached to the first interior sidewall of the housing and a free end, and wherein the at least one baffle extends from the first interior sidewall toward the second interior sidewall of the metal housing such that gases entering the interior cavity through the first opening flow along a first side of the at least one baffle, around the free end, and across a second side of the at least one baffle to exit the metal housing through the second opening, wherein the first interior sidewall and the second interior sidewall each extend between the rear interior wall and the front interior wall.

[0123] Clause 9. The hot filter assembly of clause 8, wherein the first and second interior sidewalls are opposite one another across the interior cavity.

[0124] Clause 10. The hot filter assembly of clause 9, wherein the first and second interior sidewalls are adjacent and extend perpendicular to one another with the second interior sidewall connected to a first end portion of the first interior sidewall, and wherein the attached end of the at least one baffle is attached to a second end portion of the first interior sidewall and the free end of the at least one baffle is adjacent to but spaced away from the second interior sidewall.

[0125] Clause 11. The hot filter assembly of clause 8, further comprising a wire mesh filter disposed inside the interior cavity.

[0126] Clause 12. The hot filter assembly of clause 8, wherein the metal housing comprises cast iron, and wherein the hot filter assembly is formed as one piece.

[0127] Clause 13. The hot filter assembly of clause 8, wherein the housing is open on one side and further comprising a cover coupled to the open side of the housing and defining the front interior wall of the hot filter assembly.

[0128] Clause 14. An engine system, comprising: an engine comprising a crankcase and an exhaust manifold; a turbocharger comprising a compressor and a turbine; an oil separator configured to receive blow-by gases from the crankcase and separate oil from the blow-by gases; the hot filter assembly of clause 8 coupled to the exhaust manifold of the engine or a housing of the turbine; a first conduit connecting the oil separator to the hot filter assembly, the first conduit configured to route the separated blow-by gases from the oil separator to the hot filter assembly; and a second conduit connecting the hot filter assembly to an air inlet upstream of the compressor, the second conduit configured to route cleaned and dried gases from the hot filter assembly to the air inlet.

[0129] Clause 15. The engine system of clause 14, wherein the hot filter assembly is coupled directly to an outer surface of the exhaust manifold or an outer surface of the housing of the turbine.

[0130] Clause 16. The engine system of clause 14, wherein the first conduit is a wire mesh tube comprising an outer tubing layer and an inner mesh layer, and wherein an inner diameter of the wire mesh tube is 20-30 mm and a length of the wire mesh tube is 450-550 mm.

[0131] Clause 17. The engine system of clause 14, further comprising an air filter arranged upstream of the compressor, and wherein the air inlet to which the second conduit connects is an inlet to the air filter.

[0132] Clause 18. A method of operating a turbocharger for an internal-combustion engine, comprising: routing gases that emanate from a crankcase of the engine through an oil separator and a hot filter assembly, wherein the hot filter assembly is configured to output remaining gases including particulate matter; directing the remaining gases from the hot filter assembly to a turbocharger; forming, via the particulate matter in the remaining gases, an abradable layer on at least a portion of an inlet surface of the turbocharger; and abrading, via one or more blades of a compressor of the turbocharger, the abradable layer to form an abraded surface layer between the inlet surface and the one or more blades.

[0133] Clause 19. The method of clause 18, further comprising: repeating routing of the gases, the directing of the remaining gases, the forming of the abradable layer, and the abrading of the abradable layer to maintain the abraded surface layer between the inlet surface and the one or more blades.

[0134] Clause 20. The method of clause 18, wherein the hot filter assembly is configured to output the remaining gases with the particulate matter having a size of less than or equal to 1 micron.

[0135] In view of the many possible ways in which the principles of the disclosure may be applied, it should be recognized that the illustrated configurations depict examples of the disclosed technology and should not be taken as limiting the scope of the disclosure nor the claims. Rather, the scope of the claimed subject matter is defined by the following claims and their equivalents.

Claims

1. A closed crankcase ventilation system, comprising: an engine comprising a crankcase; an oil separator coupled to the crankcase and configured to separate oil from blow-by gases received from the crankcase; and a hot filter assembly coupled to the oil separator and mounted to an exhaust manifold of the engine or a turbine housing of a turbocharger, the hot filter assembly comprising: a housing defining an interior cavity of the hot filter assembly; a gas inlet fluidly coupled between the oil separator and the interior cavity; a gas outlet fluidly coupled between the interior cavity and an air intake of the engine; and at least one baffle that extends across the interior cavity and defines a first gas pathway along a first side of the at least one baffle and a second gas pathway along a second side of the at least one baffle, wherein gases flow through the first gas pathway in a first direction and gases flow through the second gas pathway in a second direction that is opposite the first gas pathway.

2. The closed crankcase ventilation system of claim 1, further comprising a first pressure sensor at or upstream of the gas inlet of the hot filter assembly, and a second pressure sensor at or downstream of the gas outlet of the hot filter assembly.

3. The closed crankcase ventilation system of claim 1, wherein the housing of the hot filter assembly is coupled directly to an outer surface of the exhaust manifold of the engine such that heat from hot exhaust gases traveling through the exhaust manifold transfers across walls of the housing to gases flowing through the interior cavity of the hot filter assembly.

4. The closed crankcase ventilation system of claim 1, further comprising a wire mesh filter arranged inside the interior cavity.

5. The closed crankcase ventilation system of claim 1, wherein the at least one baffle includes two or more baffles spaced apart from one another and extending from opposite sidewalls of the housing in an alternating arrangement.

6. The closed crankcase ventilation system of claim 1, wherein the at least one baffle extends between a rear interior wall and a front interior wall of the housing and further extends from a first interior sidewall toward a second interior sidewall of the housing, wherein the first and second interior sidewalls extend between the rear and front interior walls.

7. The closed crankcase ventilation system of claim 1, wherein the at least one baffle extends across a majority of the interior cavity in either a longitudinal direction or a horizontal direction.

8. A hot filter assembly for an engine system, comprising: a metal housing comprising interior walls that define an interior cavity of the hot filter assembly, the interior walls comprising at least a rear interior wall, a first interior sidewall, and a second interior sidewall, and wherein the interior cavity is further defined by a front interior wall of the hot filter assembly; a first opening in communication with the interior cavity; a second opening in communication with the interior cavity; and at least one baffle arranged inside the interior cavity and extending from the rear interior wall to the front interior wall of the hot filter assembly, wherein the at least one baffle has an attached end attached to the first interior sidewall of the housing and a free end, and wherein the at least one baffle extends from the first interior sidewall toward the second interior sidewall of the metal housing such that gases entering the interior cavity through the first opening flow along a first side of the at least one baffle, around the free end, and across a second side of the at least one baffle to exit the metal housing through the second opening, wherein the first interior sidewall and the second interior sidewall each extend between the rear interior wall and the front interior wall.

9. The hot filter assembly of claim 8, wherein the first and second interior sidewalls are opposite one another across the interior cavity.

10. The hot filter assembly of claim 9, wherein the first and second interior sidewalls are adjacent and extend perpendicular to one another with the second interior sidewall connected to a first end portion of the first interior sidewall, and wherein the attached end of the at least one baffle is attached to a second end portion of the first interior sidewall and the free end of the at least one baffle is adjacent to but spaced away from the second interior sidewall.

11. The hot filter assembly of claim 8, further comprising a wire mesh filter disposed inside the interior cavity.

12. The hot filter assembly of claim 8, wherein the metal housing comprises cast iron, and wherein the hot filter assembly is formed as one piece.

13. The hot filter assembly of claim 8, wherein the housing is open on one side and further comprising a cover coupled to the open side of the housing and defining the front interior wall of the hot filter assembly.

14. An engine system, comprising: an engine comprising a crankcase and an exhaust manifold; a turbocharger comprising a compressor and a turbine; an oil separator configured to receive blow-by gases from the crankcase and separate oil from the blow-by gases; the hot filter assembly of claim 8 coupled to the exhaust manifold of the engine or a housing of the turbine; a first conduit connecting the oil separator to the hot filter assembly, the first conduit configured to route the separated blow-by gases from the oil separator to the hot filter assembly; and a second conduit connecting the hot filter assembly to an air inlet upstream of the compressor, the second conduit configured to route cleaned and dried gases from the hot filter assembly to the air inlet.

15. The engine system of claim 14, wherein the hot filter assembly is coupled directly to an outer surface of the exhaust manifold or an outer surface of the housing of the turbine.

16. The engine system of claim 14, wherein the first conduit is a wire mesh tube comprising an outer tubing layer and an inner mesh layer, and wherein an inner diameter of the wire mesh tube is 20-30 mm and a length of the wire mesh tube is 450-550 mm.

17. The engine system of claim 14, further comprising an air filter arranged upstream of the compressor, and wherein the air inlet to which the second conduit connects is an inlet to the air filter.

18. A method of operating a turbocharger for an internal-combustion engine, comprising: routing gases that emanate from a crankcase of the engine through an oil separator and a hot filter assembly, wherein the hot filter assembly is configured to output remaining gases including particulate matter; directing the remaining gases from the hot filter assembly to a turbocharger; forming, via the particulate matter in the remaining gases, an abradable layer on at least a portion of an inlet surface of the turbocharger; and abrading, via one or more blades of a compressor of the turbocharger, the abradable layer to form an abraded surface layer between the inlet surface and the one or more blades.

19. The method of claim 18, further comprising: repeating routing of the gases, the directing of the remaining gases, the forming of the abradable layer, and the abrading of the abradable layer to maintain the abraded surface layer between the inlet surface and the one or more blades.

20. The method of claim 18, wherein the hot filter assembly is configured to output the remaining gases with the particulate matter having a size of less than or equal to 1 micron.

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