A positive crankcase ventilation valve for an engine is provided with a valve body defining apertures fluidly coupling a crankcase and an intake manifold of the engine, with each aperture sized to prevent an entrained oil droplet from flowing therethrough. The valve has a valve element supported by the body to selectively cover at least one of the apertures in response to a pressure difference between the manifold and the crankcase to provide variable air flow from the crankcase to the intake manifold. A method includes, in response to an increasing absolute pressure difference between the manifold and the crankcase, passively moving a valve element to selectively cover apertures fluidly coupling the crankcase and the manifold to control an air flow from the crankcase to the intake manifold to a predetermined variable flow profile, and separating oil droplets from the air flow via the apertures.

The invention relates to an oil separating device (10) for crankcase ventilation of an internal combustion engine, comprising a carrier (11) comprising a gas inlet line (12) for flowing blow-by gas (13) having an inlet end and an outlet end, and a gap-defining element (15), wherein at least one annular gap (5, 6) is formed or can be formed between the gap-defining element (15) and the outlet end of the gas inlet line (12). A baffle wall (7, 8) is arranged downstream of the annular gap (5, 6). The oil separating device (10) comprises a circumferential wall (18), which surrounds the outer circumference of the gap-defining element (15) and is fixed relative to the carrier (11).

An air-liquid separation assembly for separating air and liquid from an air-liquid mixture comprises a housing through which fluid flows, a main separator positioned within the housing, and a sub-separator. The sub-separator is positioned within the housing before or after the main separator and defines a plurality of slots. Each of the plurality of slots is positioned either between adjacent baffles of the sub-separator or between a baffle of the sub-separator and a portion of the housing. The plurality of slots are positioned next to each other in a direction substantially perpendicular to the direction of fluid flow through the housing. The plurality of slots comprises a first subset of slots and a second subset of slots. The second subset of slots extends at a different angle than the first subset of slots such that fluid flows through the first subset of slots and the second subset of slots at different angles.

An explosion relief valve for a crankcase of an engine includes a carrier plate, a cap, and an annular flame arrestor. The carrier plate includes a valve plate that has a sinuous shape for redirecting flame back into the engine. The flame arrestor includes a plurality of layers of smooth metal sheets, with each layer having a pattern of apertures that is different in size and spacing than the pattern of apertures of its adjacent layer. The apertures of each layer are partially, and only partially, aligned with the perforations of its adjacent layers. The layers are laid flush against each other to minimize or eliminate air space between the layers, leaving only the air channels existing between the apertures of the metal sheet layers as passageways for exhaust gases to be released from the valve.

A crankcase ventilation device includes a housing and a flow directing member. The housing defines an inlet, an outlet and an internal volume. The inlet is configured to receive blow-by from an engine. The flow directing member is coupled to the housing and extends into the internal volume. The flow directing member includes a plurality of sidewalls, at least two of the plurality of sidewalls defining a window that fluidly couples the inlet to the internal volume. A filter media may be coupled to the flow directing member.

A breather chamber for an internal combustion engine wherein the breather chamber has a large size that is formed while an increase in the size of the internal combustion engine is suppressed. The breather chamber of an internal combustion engine includes looped cam chains for transmitting the power of a horizontally disposed crankshaft to camshafts provided in cylinder heads and includes cam chain chambers disposed alongside portions of cylinder block portions which intersect the direction of the crankshaft. The breather chamber is located on a side of a plane formed by a rotation locus of the cam chain in the direction of the crankshaft in the cam chain chamber.

The head cover for an engine includes a gas passage in the head cover, a gas outlet formed on a head cover wall at a terminal end portion of the gas passage in the head cover, a gas intermediate outlet portion formed in the head cover wall so as to face space inside the head cover except the gas passage in the head cover, and a gas intermediate inlet portion formed in the head cover wall so as to face the gas passage in the head cover, in which an opening specification in which through holes penetrating the head cover wall are formed and a closing specification in which the through holes are not formed can be selected for the gas intermediate outlet portion and the gas intermediate inlet portion.

This blowby gas discharging device is provided with a heating chamber 24 which is interposed midway along a blowby gas pipeline, is formed in a flywheel housing 10 of an internal combustion engine, and heats blowby gas. The internal combustion engine is provided with a power transmission mechanism 13 for transmitting power from a crankshaft 6 to a camshaft 7, and a mechanism chamber 14 accommodating the power transmission mechanism. The heating chamber is adjacent to the mechanism chamber across a separating wall 41, and a retaining portion 60 for causing oil inside the mechanism chamber to be retained is provided in the separating wall.

An explosion relief valve for a crankcase of an engine includes a carrier plate, a cap, and an annular flame arrestor. The carrier plate includes a valve plate that has a sinuous shape for redirecting flame back into the engine The flame arrestor includes a plurality of layers of smooth metal sheets, with each layer having a pattern of apertures that is different in size and spacing than the pattern of apertures of its adjacent layer. The apertures of each layer are partially, and only partially, aligned with the perforations of its adjacent layers. The layers are laid flush against each other to minimize or eliminate air space between the layers, leaving only the air channels existing between the apertures of the metal sheet layers as passageways for exhaust gases to be released from the valve.

This blowby gas discharging device is provided with a heating chamber 24 which is interposed midway along a blowby gas pipeline, is formed in a flywheel housing 10 of an internal combustion engine, and heats blowby gas. The internal combustion engine is provided with a power transmission mechanism 13 for transmitting power from a crankshaft 6 to a camshaft 7, and a mechanism chamber 14 accommodating the power transmission mechanism. The heating chamber is adjacent to the mechanism chamber across a separating wall 41, and a retaining portion 60 for causing oil inside the mechanism chamber to be retained is provided in the separating wall.