Patent attributes
A pulsating oil pressure reducing device 40 for an internal combustion engine has an oil chamber 41 for reducing pulsating oil pressure in a discharge passage 30 for carrying oil discharged from an oil pump 20. The oil chamber 41 communicates with the discharge passage 30 by way of a connecting port 41a1 and makes the oil stagnate therein. The oil chamber 41 is connected to the discharge passage 30 by an air vent passage 45 through which air is discharged from the oil chamber 41 into the discharge passage 30. The air vent passage 45 has an inlet port 45a opening into a top part 41a of the oil chamber 41 and a discharge port 45b opening into the oil passage 30 at a level above the inlet port 45a. Since the pulsating oil pressure reducing device 40 having the air vent passage separately from the connecting port, air can be efficiently discharged from the oil chamber and the degree of freedom of placement of the oil passage and the oil chamber is increased.