Patent ID: 8151776

Claim:
A breather apparatus in an engine including a cylinder head having a timing-gear chamber that accommodates a driven-side rotator fixed to one end of a rotatably supported camshaft and communicates with a crank chamber, and a side cover that is detachably mounted to a side cover attachment part, which is open to the side portion of the timing-gear chamber oppositely to a side face of the driven-side rotator, the driven-side rotator being rotatable in conjunction with a crankshaft rotatably supported within the crank chamber, the breather apparatus removing oil mist from blow-by gas in the engine and allowing the blow-by gas to be circulated into an intake system, the breather apparatus comprising: a first breather device that separates oil mist from blow-by gas in the timing-gear chamber; and a second breather device that separates and removes oil mist from blow-by gas received from the first breather device, wherein the first breather device includes: an oil separator that is attached to the one end of the camshaft so as to be rotated by the camshaft, the second breather device includes: a blow-by gas introducing passage having a blow-by gas inlet port open to the inner surface of the side cover and a closed leading end; an air-cleaner-side breather passage that extends upwardly, and has an air-cleaner-side inlet port open to the blow-by gas introducing passage and a discharge port communicating with the intake system; and a case-side breather passage that extends downwardly and has a case-side inlet port open to the blow-by gas introducing passage and a discharge port communicating with an oil chamber, wherein the blow-by gas introducing passage, the air-cleaner-side breather passage, and the case-side breather passage are formed so as to be integral with the side cover, and the oil separator of the first breather device extends about a periphery of the blow-by gas inlet port of the second breather device.