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.

A displacement machine is for acting on a working fluid and is provided with a lubricant and working fluid separator. The fluid separator has a separator volume constrained by a shielding member, a first fluid channel providing fluid communication between a first and second inner volumes and the separator volume, a second fluid channel providing fluid communication between the separator volume and a working fluid return volume. The fluid separator, the first fluid channel and the second fluid channel are fully contained within a full volume of the displacement machine. A method is for separating lubricant and working fluid in a displacement machine.

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.

A blow-by gas recirculation device that, while having a structure in which a passage for blow-by gas is in a head cover and an oil separator, an increase in size of an engine is suppressed and the risk of the freezing is mostly avoided by shortening the length of an external pipe for the blow-by gas. Therefore, the blow-by gas recirculation device guides blow-by gas from a crankcase to an intake passage through an in-cover gas passage formed inside a head cover. An oil separator that traps and removes oil from the blow-by gas is attached to the inside of the head cover. A pressure regulating valve is provided on the outlet side of the in-cover gas passage in the head cover. A separator outlet, which is an outlet for the blow-by gas in the oil separator, is overlapped on a blow-by gas inlet portion of the pressure regulating valve.

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.

There are provided a synthetic resin joined body and a method of manufacturing the same, with which it is possible to secure both of sealing performance of a fluid passage and joint strength between synthetic resin parts, even if an area of a portion to be welded is reduced. The synthetic resin joined body includes: a baffle plate; an oil passage forming member which comes in contact with the baffle plate; an oil passage which is formed between the baffle plate and the oil passage forming member and through which lubricant flows; a sealing portion which is formed by welding the baffle plate and the oil passage forming member to each other on an outer side of the oil passage to seal a periphery of the oil passage; and a joint portion for joining the baffle plate and the oil passage forming member to each other.

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 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.