A cylinder head cover integrated with an active oil mist separator may include a cylinder head cover body, a booster, and an oil mist separator. The cylinder head cover body may be provided with an exhaust passage and a separation passage. The booster may be mounted outside the cylinder head cover body. The booster may have a booster intake port and a booster exhaust port. The booster intake port may be connected with the exhaust passage. The booster exhaust port may be connected with the separation passage. The oil mist separator may be mounted in the separation passage and the oil mist separator may be located on a downstream side of the booster.

The blow-by gas treating device 100 has a main structure portion 101 which separates oil OL from the blow-by gas BG and an outlet portion 40 which supplies gas G having been separated from the blow-by gas BG to an intake system. The main structure portion 101 has a first blow-by gas taking-in portion 111, a second blow-by gas taking-in portion 112, a separating portion 330 which separates the blow-by gas BG into oil OL and gas G, a first oil guiding portion 151 which guides the oil OL to a front side, a second oil guiding portion 152 which guides the oil OL to a rear side, a first oil drain 161 which discharges the oil OL into the engine, and a second oil drain 162 which discharges the oil OL into the engine.

This breather device separates engine oil included in a blow-by gas. The breather device comprises a first route, an acceleration route, a branching route, and turn-back routes. The blow-by gas flows to the first route. The acceleration route is connected to a downstream side of the first route, and has a flow channel cross-sectional area smaller than that of the first route. The branching route is connected to a downstream side of the acceleration route, configured including a wall part orthogonal to the acceleration route, and branched into two routes by the wall part. The turn-back routes are connected to one route branching at the branching route, and are turned back so as to be parallel to the acceleration route and to head in the opposite direction from a progressing direction.

An internal combustion engine includes a crankcase with a plurality of piston-cylinder arrangements and a valve head positioned above the crankcase at least in part containing a valve train. The internal combustion engine further includes a head cover coupled to the valve head and having a blowby outlet and a baffle positioned between the head cover and the crankcase and defining an oil passage internal to the baffle. Engine oil circulates through the oil passage of the baffle to transfer heat to blowby gas flowing from one or more of the plurality of piston-cylinder arrangements before exiting the valve head through the blowby outlet in the head cover.

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.

A vehicular internal combustion engine is equipped with a supercharger, a drain pipe for draining lubricating oil in the supercharger, a cylinder block including a first oil passage, and a PCV separator including a second oil passage connected to an outlet of the drain pipe and an inlet of the first oil passage.

Engine includes: crankcase housing crankshaft extending in vertical direction; cylinder block mounted on side of crankcase and formed with cylinder; cylinder head mounted on side of cylinder block and provided with air inlet port and air outlet port communicating with cylinder; cylinder head cover mounted on side of cylinder head and covering air inlet port and air outlet port; mount case including: supporting portion provided below crankcase and cylinder block and supporting crankcase and cylinder block; and extending portion extending from supporting portion below cylinder head and cylinder head cover; oil pan provided below mount case and storing lubricating oil; and communication tube communicating first space formed between cylinder head and cylinder head cover and second space formed between mount case and oil pan. Communication tube is provided between cylinder head cover and extending 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.

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.

An oil separator for an internal combustion engine includes a case and a separation wall. The case includes inflow ports into which blow-by gas flows, a gas outflow port, and an oil discharge port. An inside of the case is divided by the separation wall into an upstream passage and a downstream passage. The downstream passage is located on the upper side of the upstream passage. The inflow ports and the oil discharge port are connected to the upstream passage. The gas outflow port is connected to the downstream passage. The inflow ports and the oil discharge port are arranged in a direction intersecting the vertical direction. The separation wall includes one connection passage that connects the upstream passage to the downstream passage on the upper side of the oil discharge port. The separation wall is located on the upper side of the inflow ports.