There is provided a breather chamber structure. An inner wall partitions a breather space surrounded by outer walls into a plurality of chambers including a first chamber, a second chamber, and a third chamber. An inlet allows the gas to flow into the first chamber. A first communication path communicates between the first chamber and the second chamber. A second communication path communicates between the second chamber and the third chamber. An outlet allows the gas in the third chamber to flow out of the breather space. An oil discharge port is configured to return oil separated from gas in the breather space to an oil reservoir. The third chamber has a volume equal to or greater than half of a volume of the breather space. The first chamber has a volume larger than a volume of any of the chambers except for the first and third chambers.

A device separates particles such as oil particles from a gas flow, from a blow-by gas of a crankcase ventilation, in an internal combustion engine. The device includes a valve seat that defines a flow passage opening and a movable valve element that can be displaced between a closed position, in which the valve element is in abutting contact with the valve seat and the abutting contact defines an axial abutting point, and at least one open position, in which the valve element is moved from the axial abutting point in an axial actuating direction. The movable valve element has a rotationally symmetrical bowl upstream of the gas flow, and a base of the bowl axially protrudes past the abutting point opposite to the axial actuating direction.

An oil separating device for separating an oil mist from a blow-by gas is arranged on a flow passage of the blow-by gas. The oil separating device includes an oil separator having an inlet formed at one end thereof and an outlet formed at another end thereof opposite to the one end; a collision wall arranged at a downstream side of the oil separator, and including an uneven portion formed on a surface thereof to face the outlet of the oil separator; and a filter arranged between the oil separator and collision wall. The oil separator is formed such that the oil mist in the blow-by gas coalesces together to form a coalesced oil mist, the filter removes the coalesced oil mist from the blow-by gas, and the collision wall separates a remained oil mist remained in the blow-by gas through the filter.

A positive crankcase ventilation (PCV) system for an internal combustion engine having an air induction system configured to supply air to the includes a PCV line configured to fluidly couple between a crankcase of the engine and the air induction system, a condenser disposed on the PCV line and configured to condense water vapor and fuel vapor contained in blow-by gases received from the crankcase to separate the water vapor and fuel vapor from the blow-by gases and form a water/fuel mixture and a lean blow-by gas, and an oil separator disposed on the PCV line and configured to receive the lean blow-by gas from the condenser and separate oil therefrom to form a filtered blow-by gas for return to the air induction system.

Methods and systems are provided for diagnosing a positive crankcase ventilation (PCV) system. In one example, a diagnostic method for a PCV system is provided that includes, when an intake manifold air pressure is above a threshold boost value, determining a PCV system breach based on a pressure determined using a pressure sensor positioned on a clean side of an oil separator coupled to a crankcase and receiving crankcase gas from the crankcase. In the PCV system a ventilation line provides fluidic communication between the oil separator and an intake conduit upstream of a compressor.

There is provided a breather chamber structure. An inner wall partitions a breather space surrounded by outer walls into a plurality of chambers including a first chamber, a second chamber, and a third chamber. An inlet allows the gas to flow into the first chamber. A first communication path communicates between the first chamber and the second chamber. A second communication path communicates between the second chamber and the third chamber. An outlet allows the gas in the third chamber to flow out of the breather space. An oil discharge port is configured to return oil separated from gas in the breather space to an oil reservoir. The third chamber has a volume equal to or greater than half of a volume of the breather space. The first chamber has a volume larger than a volume of any of the chambers except for the first and third chambers.

A device separates particles such as oil particles from a gas flow, from a blow-by gas of a crankcase ventilation, in an internal combustion engine. The device includes a valve seat that defines a flow passage opening and a movable valve element that can be displaced between a closed position, in which the valve element is in abutting contact with the valve seat and the abutting contact defines an axial abutting point, and at least one open position, in which the valve element is moved from the axial abutting point in an axial actuating direction. The movable valve element has a rotationally symmetrical bowl upstream of the gas flow, and a base of the bowl axially protrudes past the abutting point opposite to the axial actuating direction.

A system includes an air chamber and an oil capture cavity. The air chamber includes an inlet to receive pressurized air from a gas turbine engine. The oil capture cavity is positioned between the air chamber and an oil sump supplying lubricating oil to the gas turbine engine. The oil capture cavity includes an auxiliary vent formed in a base of the oil capture cavity. A seal may separate the oil capture cavity from fluid communication with the oil sump. A nozzle provides fluid communication between the oil capture cavity and the air chamber. The nozzle is configured and positioned to direct a stream of the pressurized air into the oil capture cavity against an opposite wall of the oil capture cavity to create a quiescent zone at the base of the oil capture cavity. The quiescent zone includes the auxiliary vent.

An internal combustion engine includes: a cylinder having a combustion chamber formed at an upper side thereof and accommodating a piston to be reciprocally movable; a crankcase provided below the cylinder and accommodates a crankshaft; and a blow-by gas passageway recirculating blow-by gas, which leaks into the crankcase from the combustion chamber, to the combustion chamber through an intake system, in which an inner surface portion of the crankcase is provided with a blow-by gas intake part, and the blow-by gas intake part includes a protruding portion protruding in a direction in which the crankshaft extends, and the intake port opened in the protruding direction is formed at a tip end portion of the protruding portion.

In an internal combustion engine, the cylinder block includes a first blowby gas passage and a first oil return passage. The cylinder head includes a second blowby gas passage connecting the first blowby gas passage with a connection passage connected with a gas-liquid separator, an oil return chamber separated from a valve operating chamber and the second blowby gas passage by first and second partition walls, respectively, and provided with a first oil return hole connected with the gas-liquid separator, and a second oil return passage connecting the valve operating chamber with the first oil return passage. The first partition wall is formed with a second oil return hole connecting the oil return chamber with the valve operating chamber. The second partition wall is formed with a ventilation hole connecting the oil return chamber with the second blowby gas passage at a higher position than the second oil return hole.