An oil return valve for a crankcase ventilation system of an internal combustion engine is provided that is essentially situated in the crankcase (3) and includes a valve cylinder (1) and at least one valve pipe (2).

An improved blow-by gas return structure minimizes the occurrence of a drawback caused by freezing at a low temperature by bringing a state where freezing minimally occurs in a blow-bay gas passage such as a pipe disposed outside an engine. The blow-by gas return structure is configured such that a blow-by gas is introduced into an intake manifold through an inner passage formed in a head cover. The blow-by gas return structure includes an outer pipe which connects a blow-by gas outlet of the head cover and a blow-by gas inlet of a main pipe of the intake manifold in a communicable manner, and a temperature elevating mechanism configured to elevate a temperature of the blow-by gas inlet. The temperature elevating mechanism is configured such that a cooling water transfer passage is formed in a portion of the blow-by gas inlet of the main pipe.

A gas-liquid separation device includes a gas-liquid separation chamber in a head cover that defines a valve gear chamber, a partition wall that changes a direction of blow-by gas that flows in the gas-liquid separation chamber, and a blow-by gas suction passage extending from the gas-liquid separation chamber to an intake-side valve gear chamber. The upstream end of the blow-by gas suction passage defines an opening in a vicinity of a bottom wall of the valve gear chamber (intake-side valve gear chamber). The gas-liquid separation device removes an oil mist in the blow-by gas while using a compact and simple gas-liquid separation structure.

An internal combustion engine includes a crankcase having first and second pluralities of openings. A oil separation module has at least one inlet housing that communicates with a oil separation filter and is connectable to at least one opening from the first plurality of openings or from the second plurality of openings to define a crankcase vent.

A separator device for a system for recirculation of the blow-by gases of an internal combustion engine includes a casing containing a separation chamber and having an inlet for communication with the engine crankcase and an outlet for communication with the engine intake manifold, and drainage outlets ending in the engine crankcase, for returning the liquid separated in the separation chamber into the engine crankcase. Actuator means sensitive to pressure in the engine crankcase are associated to the inlet and to the drainage outlets so that when the pressure in the engine crankcase is higher than the pressure in the separator device, the inlet is open and the drainage outlets are closed, while when the pressure in the engine crankcase is lower than the pressure in the separator device, the inlet is closed and the drainage outlets are open.

A rotating separator including a filter element extending axially along a longitudinal axis and including a first endplate, a second endplate, and a separating element. The first endplate includes a center tube. The second endplate is coupled to the first endplate and includes a central aperture having a perimeter and receiving the center tube. The filter element also includes an axially extending slot and an axially extending protrusion positioned on one of the first endplate and the second endplate and configured to engage with each other. The first and second endplates form an interior cavity when coupled together. The rotating separator includes a filter structure positioned within the interior cavity.

This oil return structure is provided with a flow passage body configured to return oil into an engine body which communicates with an oil storage section of the engine, the oil having been separated from a blow-by gas by an oil separation means. The upstream end of the flow passage body is connected to the oil separation means, at least a portion of the downstream side of the flow passage body protrudes into the engine body from the inner wall thereof, and an oil discharge opening at tire downstream end of the flow passage body is disposed at a position not immersed in oil within the oil storage section.

In a combustion engine, an exit stream of blow-by gases follows a fluid pathway through an oil and air separator and a breather filter, the oil and air separator including a first housing including a central chamber therein, the central chamber divided into a first outer portion and a second inner portion by a barrier; a filter material disposed between the first outer portion and the second inner portion; a cap directly coupled to the first housing, the cap including a first lumen therethrough, the first lumen including a first end disposed at the second inner portion; and a coupler removably coupling the cap and an extension portion including a second lumen therethrough.

An engine includes: an exhaust manifold 7 close to one of left and right side surfaces of an engine; a turbocharger 60 having an exhaust-side inlet connected to the exhaust manifold 7; and a rocker-arm-chamber-integrated intake manifold 8 being disposed on an upper surface of a cylinder head 5 and integrally including a rocker arm chamber 90 and an intake manifold 6. The intake manifold 8 has a wall 101 dividing the rocker arm chamber 90 close to the one of the left and right side surfaces of the engine 1 and the intake manifold 6 close to the other of the left and right side surfaces to isolate the rocker arm chamber 90 and the intake manifold 6 from each other. The rocker arm chamber 90 has, in its upper portion, a positive crankcase ventilation device 69 protruding therefrom and being configured to return blowby gas to an intake system. The positive crankcase ventilation device 69 has, in its side surface, a blowby-gas discharge port 67 connected with a gas conduit 68 through which blowby gas is delivered to an intake-side inlet of the turbocharger 60.

A breather is provided for an internal combustion engine that is configured to be mounted to provide a compact, space efficient packaging arrangement for the internal combustion engine. The breather includes a housing with a front wall, a rear wall opposite the front wall, and a plurality of sidewalls connecting the front and rear walls. The front wall is configured for attachment to the rearward end of the valve cover.