A positive crankcase ventilation system includes a positive crankcase ventilation valve, a coupling part, and a plate member. The coupling part is configured to couple the positive crankcase ventilation valve and an internal combustion engine. The plate member is attached to the coupling part on an opposite side from a side where the coupling part and the internal combustion engine contact each other. A portion of the plate member is bent in a direction toward a base of a hose insertion port provided on the positive crankcase ventilation valve, and another portion of the plate member is bent in a direction toward a side wall of an attachment portion of the positive crankcase ventilation valve provided on the coupling part.

A lubricant supply apparatus for an internal combustion engine includes a lubricant shower and a baffle plate. The lubricant shower is disposed between a camshaft and a cylinder head cover attached to a cylinder head. The lubricant shower includes a supply port from which a lubricant is supplied to the camshaft. The baffle plate is disposed between the camshaft and the lubricant shower such that a clearance is provided between the baffle plate and the lubricant shower. The baffle plate includes a hole provided at a position at which the hole of the baffle plate overlaps with the supply port of the lubricant shower. The camshaft is provided with a cam. The supply port of the lubricant shower and the hole of the baffle plate are located above the cam.

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.

An engine assembly includes an engine, an intake assembly, and an air-oil separator. The engine defines a combustion chamber and a crankcase. The intake assembly includes an intake manifold wherein the intake manifold is in fluid communication with the combustion chamber. The air-oil separator defines an internal passageway having a separator volume and further defining an inlet and outlet in fluid communication with the separator volume. The inlet of the air-oil separator may be in fluid communication with the crankcase while the outlet of the air-oil separator may be in fluid communication with the intake manifold. The air-oil separator further includes a fine separator disposed across the internal passageway proximate to the inlet wherein the fine separator includes a curved backplate and a front plate.

The ventilator-equipped engine is configured to: guide a blow-by gas generated in a crankcase to an intake passage through an inside of a cylinder head, an inside of a head cover, and a pressure regulating valve; and to directly introduce fresh air into an internal space of the cylinder head by providing a fresh air introduction passage that extends across the intake passage and the cylinder head.

A separator includes: a filter device that receives oil-containing blow-by gases from an engine and separates at least a portion of oil from the oil-containing blow-by gases, the oil-containing blow-by gases being generated by the engine; a screen extending from the filter device in a direction transverse to a vertical direction with respect to the engine; a drain hole vertically penetrating below the screen to allow the separated oil to be discharged by gravity; and a gas outlet disposed above the screen to discharge the separated blow-by gases.

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.

The present invention relates to an oil separating device for crankcase ventilation of an internal combustion engine, comprising an oil separator having a gas inlet line, which has an outlet end, and a gap-defining element, wherein the gas inlet line for flowing blow-by gas has an inner wall and an outer wall, wherein an inner annular gap is formed or can be formed between the gap-defining element and the outlet end on the inner wall of the gas inlet line and an outer annular gap is formed or can be formed between the gap-defining element and the outlet end of the outer wall of the gas inlet line, wherein, in the flow direction, an inner baffle is arranged behind the inner annular gap and an outer baffle is arranged behind the outer annular gap.

In an engine that includes a blow-by-gas returning system configured to direct blow-by gas within a crankcase to an intake system through an inside of a head cover, the intake system includes a cover intake-passage disposed at a blow-by-gas outlet of the head cover, and the cover intake-passage communicates with a blow-by-gas passage of the blow-by-gas outlet.

The disclosure prevents oil separated from blow-by gas by using a breather chamber and discharged to a valve chamber from leaking to the outside from a breather chamber mounting surface between the breather chamber and the valve chamber. A breather chamber includes cylindrical drain passages communicating with a valve chamber, and tips of the drain passages exceed breather chamber mounting surfaces of a cylinder head and a head cover and protrude from opening parts toward a side of the valve chamber, so the oil separated from the blow-by gas in the breather chamber can be reliably discharged to the valve chamber and prevented from leaking to the outside from the breather chamber mounting surfaces.