Crank chamber internal pressure reduction mechanism for internal combustion engine

Abstract

A crank chamber internal pressure reduction mechanism for internal combustion engine includes a crankshaft, a rotating shaft (a balancer shaft), a suction mechanism (a primary drive gear), a first discharge passage (a discharge passage, a joining passage, and a discharge hose), and a second discharge passage (a discharge passage). The crankshaft is rotatably supported to a crankcase. To the rotating shaft, a rotation force is transmitted from the crankshaft. The suction mechanism is disposed at the rotating shaft. The suction mechanism rotates integrally with the rotating shaft. To the first discharge passage, the emission is discharged from the crank chamber. The second discharge passage is communicated with the first discharge passage. The second discharge passage is disposed inside the rotating shaft. The suction mechanism includes a third discharge passage (a hole). The third discharge passage is communicated with the second discharge passage. The third discharge passage extends outside the rotating shaft in a radial direction to communicate with an external space.

Dependencies are inferred from the claim text.