Patent attributes
First and second pressure relief passages extend from an oil pan in a branching manner, and merge with each other to form a merging portion. A pressure relief hole is arranged above the merging portion, and a first pressure relief passage is arranged below the merging portion. The minimum cross-sectional area of the second pressure relief passage is smaller than the minimum cross-sectional area of the first pressure relief passage. The second pressure relief passage includes a bent portion formed by bending the second pressure relief passage. The bent portion is configured to perform gas/liquid separation by crushing bubbles. When reaching the merging portion from the bent portion, oil is returned to the oil pan via the first pressure relief passage. When reaching the merging portion from the bent portion, gas is discharged to the outside of the housing via the pressure relief hole.
