Internal combustion engine and crankcase ventilation system

An internal combustion engine includes a block containing a crankshaft and a crankcase surrounding the crankshaft, a plurality of combustion chambers configured to receive an intake fluid and generate exhaust fluid, an exhaust circuit configured to direct the exhaust fluid away from the plurality of combustion chambers, an intake circuit configured to supply the intake fluid to the plurality of combustion chambers, a turbine disposed in the exhaust circuit and having a turbine shaft configured to be driven by the exhaust fluid, a crankcase ventilation circuit configured to direct crankcase fluid away from the crankcase, and a pump disposed in the crankcase ventilation circuit and having a rotor configured to be driven by the turbine shaft to propel the crankcase fluid through the crankcase ventilation circuit.

BACKGROUND

Internal combustion engines may generate blowby gas during engine operation such as by intake air and exhaust gases traveling past piston rings, stem seals, compressor or turbine seals, or other engine components. Gaseous crankcase fluid, include blowby gas, is mostly contained in the crankcase where its pressure may be regulated using an open or closed crankcase ventilation system. In an open crankcase ventilation system, the crankcase fluid may be ventilated out of the engine to regulate crankcase pressure. In a closed crankcase ventilation system, the crankcase fluid may be ventilated into an intake air circuit or another location having a pressure below the pressure of the crankcase fluid such that the crankcase fluid is reintroduced to the engine.

SUMMARY

Various aspects of examples of the present disclosure are set out in the claims.

In an embodiment of the present disclosure, an internal combustion engine includes a block containing a crankshaft and a crankcase surrounding the crankshaft, a plurality of combustion chambers configured to receive an intake fluid and generate exhaust fluid, an exhaust circuit configured to direct the exhaust fluid away from the plurality of combustion chambers, an intake circuit configured to supply the intake fluid to the plurality of combustion chambers, a turbine disposed in the exhaust circuit and having a turbine shaft configured to be driven by the exhaust fluid, a crankcase ventilation circuit configured to direct crankcase fluid away from the crankcase, and a pump disposed in the crankcase ventilation circuit and having a rotor configured to be driven by the turbine shaft to propel the crankcase fluid through the crankcase ventilation circuit.

The engine may further include a compressor disposed in the intake circuit propelling the intake fluid to the plurality of combustion chambers. The engine may further include a crankcase ventilation circuit outlet disposed at the intake circuit downstream from the compressor such that the crankcase fluid is propelled from the crankcase to the intake circuit through the crankcase ventilation circuit. The engine may further include a separator disposed in the crankcase ventilation circuit and configured to remove a lubricant from the crankcase fluid as the crankcase fluid is directed through the crankcase ventilation circuit. The separator may be disposed upstream of the pump in the crankcase ventilation circuit. The engine may further include a regulator disposed in the crankcase ventilation circuit and configured to regulate the pressure of the crankcase fluid in the crankcase. The regulator may be disposed upstream of the pump in the crankcase ventilation circuit. The engine may further include a check valve disposed in the crankcase ventilation circuit and configured to prevent a reverse flow direction of the crankcase fluid from the crankcase ventilation circuit outlet toward the pump. The check valve may be disposed downstream of the pump in the crankcase ventilation circuit. The engine may further include a crankcase ventilation circuit outlet disposed at the exhaust circuit downstream of the turbine such that the crankcase fluid is propelled from the crankcase to the exhaust circuit through the crankcase ventilation circuit.

In an embodiment of the present disclosure, a crankcase ventilation system is configured to ventilate a crankcase in an internal combustion engine having a turbine. Th crankcase ventilation system includes a crankcase ventilation circuit configured to direct crankcase fluid away from the crankcase, a pump disposed in the crankcase ventilation circuit and being configured to be driven by the turbine to propel the crankcase fluid through the crankcase ventilation circuit, a check valve disposed in the crankcase ventilation circuit downstream of the pump and being configured to prevent a reverse flow direction of the crankcase fluid toward the pump, and a separator disposed in the crankcase ventilation circuit and configured to remove a lubricant from the crankcase fluid as the crankcase fluid is directed through the crankcase ventilation circuit.

The separator may be disposed in the crankcase ventilation circuit upstream of the pump. The system may further include a crankcase ventilation circuit outlet configured to be positioned at an intake circuit downstream of a compressor propelling an intake fluid in the intake circuit, wherein the crankcase fluid may be propelled from the crankcase to the intake circuit through the crankcase ventilation circuit. The system may further include a crankcase ventilation circuit outlet configured to be positioned at an exhaust circuit downstream of the turbine, wherein the crankcase fluid may be configured to be propelled from the crankcase to the exhaust circuit through the crankcase ventilation circuit.

The above and other features will become apparent from the following description and accompanying drawings.

Like reference numerals are used to indicate like elements throughout the several figures.

DETAILED DESCRIPTION

At least one embodiment of the subject matter of this disclosure is understood by referring toFIGS.1through5of the drawings.

Reference is now made toFIG.1, which illustrates an internal combustion engine10and a crankcase ventilation system100in accordance with one or more embodiments of the present disclosure. The engine10includes a block12containing or including a crankshaft14and a crankcase16surrounding or otherwise disposed around the crankshaft14. The engine10further includes a plurality of cylinders18, each having a combustion chamber20configured to receive an intake fluid22and generate an exhaust fluid24, such as, in a non-limiting example, an exhaust gas formed by combustion of a fuel mixed with the intake fluid22in the combustion chamber20. The fuel may be supplied via one or more fuel injector(s) (not shown). The intake fluid22may include a fuel and/or another liquid or gaseous material. The engine10of the illustrated embodiment includes an intake manifold26through which the intake fluid22flows and an exhaust manifold28through which the exhaust fluid24flows.

The engine10further includes an exhaust circuit30configured to direct the exhaust fluid24away from the combustion chambers20. The engine10further includes an intake circuit32configured to supply the intake fluid22to the combustion chambers20. The engine10illustrated inFIG.1includes a turbocharger34having a turbine36disposed in the exhaust circuit30. The turbine36includes a turbine shaft96configured to be rotated or otherwise driven by the exhaust fluid24. In an embodiment, the turbocharger34of the engine10includes a compressor38disposed in the intake circuit32propelling the intake fluid22to the combustion chambers20. The compressor38illustrated inFIG.1is directly coupled to the turbine36. In one or more additional embodiments, the engine10does not include the compressor38, the turbine36is not directly coupled to the compressor38, the turbine36is rotationally coupled to a motor/generator and/or the compressor38is rotationally coupled to a motor/generator.

The engine10and system100ofFIG.1includes a crankcase ventilation circuit40configured to direct a crankcase fluid42away from the crankcase16. The crankcase ventilation circuit40extends from a crankcase ventilation circuit inlet44disposed at the crankcase16to a crankcase ventilation circuit outlet46.

The engine10and the system100illustrated in the embodiment ofFIG.1includes a crankcase ventilation circuit outlet46disposed at the intake circuit32downstream from the compressor38such that the crankcase fluid42is propelled from the crankcase16to the intake circuit32through the crankcase ventilation circuit40. Accordingly, the crankcase fluid42in the engine10and the system100ofFIG.1returns to the engine10through the intake circuit32in a closed crankcase ventilation system.

Referring now toFIG.2, the crankcase ventilation circuit outlet46of an embodiment is disposed at the exhaust circuit30downstream of the turbine36such that the crankcase fluid42is propelled from the crankcase16to the exhaust circuit30through the crankcase ventilation circuit40. Accordingly, the crankcase fluid42in the engine10and the system100ofFIG.2is directed away from the engine10through the exhaust circuit30in an open crankcase ventilation system.

Referring now toFIG.3with ongoing reference toFIGS.1and2, a pump48is disposed in the crankcase ventilation circuit40. The pump48includes a rotor50or other working component including, without limitation, an impeller58or other component configured to impart fluid motion to the crankcase fluid42. The pump48illustrated inFIG.3includes a volute60or similar flow channel disposed between a first pump housing member66and a second pump housing member68, an inlet port62, and a discharge port64. The rotor50and/or the impeller58is/are configured to be directly or indirectly rotated by, driven by, or otherwise powered by the turbine shaft96to propel the crankcase fluid42through the crankcase ventilation circuit40. In additional embodiments not illustrated, the rotor50or the pump48is not powered by the turbine36or another portion of the turbocharger34, but is instead powered by electrical, hydraulic, pneumatic, belt, gear, or other mechanical means. In the illustrated embodiment, the rotor50is directly coupled to the turbine shaft96. In additional embodiments not illustrated, the rotor50may be powered indirectly by the turbine shaft96such as by, in non-limiting examples, electrical, pneumatic, hydraulic, or indirect mechanical connection between the turbine shaft96and the rotor50and/or another component of the pump48. In one or more additional embodiments not illustrated, the pump48may be or include another structure and/or may operate under a different principle, including without limitation a peristaltic, diaphragm, Roots-type, Moineau-type, gear, gerotor, piston, or other type of centrifugal flow, axial flow, positive displacement, reciprocating, or other pump type.

In order to handle the crankcase fluid42, the rotor50, the impeller58, the volute60, and/or another portion of the pump48and/or other component of the crankcase ventilation circuit40of one or more embodiments includes one or more corrosion resistant materials, coatings, and/or treatments, such as certain components being made from stainless steel in a non-limiting example. Additionally, in one or more additional embodiments, the pump48and/or another component of the crankcase ventilation circuit40includes one or more gaseous or liquid heat exchangers, such as, in non-limiting examples, air, water, or coolant jackets, passages, fins, or features, in order to cool the pump48and/or other component and prevent or reduce coking of the crankcase fluid42.

Referring now toFIG.4with ongoing reference toFIGS.1and2, the engine10further includes a separator52disposed in the crankcase ventilation circuit40. As illustrated inFIG.4, the separator52, such as an impactor separator in a non-limiting example, is configured to remove a lubricant, such as oil droplets70in a non-limiting example, from the crankcase fluid42as the crankcase fluid42is directed through the crankcase ventilation circuit40. The separator52of the embodiment illustrated inFIG.4includes nozzles72or other passage(s) upstream of an impactor surface74, such as a fleece impactor surface in a non-limiting example, and a lubricant drain76disposed between the nozzles72and the impactor surface74. In the embodiment illustrated inFIG.4, the crankcase fluid42having oil droplets70flows through the nozzles72before impinging upon or otherwise contacting the impactor surface74. The oil droplets70accumulate on the impactor surface74and fall by gravity or are otherwise directed to the lubricant drain76. The crankcase fluid42flows downstream of the impactor surface74with oil droplets70removed from the crankcase fluid42. The oil or lubricant that reaches the lubricant drain76is returned to the engine10via a lubricant circuit78. The separator52of additional embodiments not illustrated is or includes, in non-limiting examples, one or more baffle(s), blowby driven impactor(s), variable blowby driven impactor(s), cyclonic impactor(s), rotating coalescing filter(s), or centrifugal hydraulically or electrically driven or boost driven separator(s).

The separator52of the illustrated embodiments is disposed upstream of the pump48in the crankcase ventilation circuit40. The separator52reduces or prevents oil droplets70reaching the pump48, another component in the crankcase ventilation circuit40, and/or the intake circuit32or the exhaust circuit30, depending on the arrangement of the crankcase ventilation circuit40. Such prevention or reduction via the separator52improves the efficiency, durability, and performance of the pump48and other components of the engine10and the system100.

Referring now toFIG.5with continuing reference toFIG.1, a regulator54is disposed in the crankcase ventilation circuit40. The regulator54is a crankcase pressure regulator in an embodiment configured to regulate the pressure of the crankcase fluid42in the crankcase16. In the non-limiting example of the regulator54illustrated inFIG.5, the regulator54is a crankcase depression regulator that includes a regulator housing88, a regulator inlet80, a regulator outlet82, a regulator diaphragm84, and a spring86. However, one will appreciate that the regulator54of additional embodiments includes alternative structure or operation configured to regulate the pressure of the crankcase16. The regulator54is disposed upstream of the pump48in the crankcase ventilation circuit40.

During operation of an embodiment, as the speed of the turbine shaft96and/or the rotor50increases, the regulator54actuates toward closing the crankcase ventilation circuit40in order to maintain the flow rate in the crankcase ventilation circuit40. Such actuation of the regulator54varies in one or more embodiments depending upon altitude of the engine10during operation, engine load, and/or one or more additional factors or conditions. Further, in an additional embodiment, a crankcase pressure sensor (not shown) may be provided to send feedback, such as to a controller, for operation of an electronically controlled regulator.

The engine10of one or more embodiments further includes a check valve56disposed in the crankcase ventilation circuit40. The check valve56is configured to prevent a reverse flow direction of the crankcase fluid42from the crankcase ventilation circuit outlet46toward the pump48. In other words, the check valve56allows flow of the crankcase fluid42from the pump48through the check valve56but prevents flow of the crankcase fluid42in a direction toward the pump48and/or the crankcase16. The check valve56in an embodiment is disposed downstream of the pump48in the crankcase ventilation circuit40. The check valve56in additional embodiments is disposed upstream of the pump48or at another location in the crankcase ventilation circuit40. In the embodiment(s) that may include an electronically controlled regulator, the check valve56may be omitted.

The engine10and the system100of the embodiments described herein provide crankcase ventilation for crankcase fluid42, such as blowby gases, generated within the engine10. More particularly, the pump48and/or other components of the engine10and the system100allow the crankcase fluid42to be circulated as a gas to a location having a higher pressure than a pressure in the crankcase16. In embodiments where the crankcase ventilation circuit outlet46is located in the intake circuit32, the engine10and the system100provide a closed crankcase ventilation system that circulates the crankcase fluid42downstream of the compressor38to avoid introducing the crankcase fluid42to the compressor38and thereby causing adverse effects to the compressor38or its performance. Likewise, in embodiments where the crankcase ventilation circuit outlet46is located in the exhaust circuit30, the engine10and the system100provide an open or semi-open crankcase ventilation system that circulates the crankcase fluid42downstream of the turbine36to avoid introducing the crankcase fluid42to the turbine36and thereby causing adverse effects to the turbine36or its performance.

As used herein, “e.g.” is utilized to non-exhaustively list examples and carries the same meaning as alternative illustrative phrases such as “including,” “including, but not limited to,” and “including without limitation.” As used herein, unless otherwise limited or modified, lists with elements that are separated by conjunctive terms (e.g., “and”) and that are also preceded by the phrase “one or more of,” “at least one of,” “at least,” or a like phrase, indicate configurations or arrangements that potentially include individual elements of the list, or any combination thereof. For example, “at least one of A, B, and C” and “one or more of A, B, and C” each indicate the possibility of only A, only B, only C, or any combination of two or more of A, B, and C (A and B; A and C; B and C; or A, B, and C). As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Further, “comprises,” “includes,” and like phrases are intended to specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof.

While the present disclosure has been illustrated and described in detail in the drawings and foregoing description, such illustration and description is not restrictive in character, it being understood that illustrative embodiment(s) have been shown and described and that all changes and modifications that come within the spirit of the present disclosure are desired to be protected. Alternative embodiments of the present disclosure may not include all of the features described yet still benefit from at least some of the advantages of such features. Those of ordinary skill in the art may devise their own implementations that incorporate one or more of the features of the present disclosure and fall within the spirit and scope of the appended claims.