Abstract: An improvement in an oil filter is provided, the oil filter being of the type which comprise a housing opened at one end thereof, a cylindrical first separator unit disposed in the housing for removing solid contaminants from the oil introduced into the housing, and a second separator unit disposed within the first separator unit for removing gaseous contaminants from the oil that has passed through the first separator unit, the second separator unit including a funnel-shaped cyclone defining a chamber arranged to generate a vortical flow of the oil introduced therein to thereby separate gas-rich oil and a removal pipe extending into the chamber along an axial center thereof for discharging the gas-rich oil. The improvement comprises a wall of the cyclone defining the chamber having a lower portion and an upper portion, and a plurality of pores formed in the lower portion for allowing the oil to flow out of the cyclone.

Abstract: An oil filter comprising a housing opened at one end, a first separator unit in the housing for removing solid contaminants from the oil and a second separator unit for removing gaseous contaminants. The first separator unit includes a cylindrical filter element and upper and lower end plates attached to the upper and lower ends of the filter element. The second separator unit is disposed in the space defined by the inner periphery of the filter element and between the upper and lower end plates. It includes a chamber arranged to generate a vortical flow of the oil introduced thereof to thereby separate gas-rich oil which gathers in an axially central portion of the chamber, a first outlet for discharging the gas-rich oil and a second outlet for the oil containing little gaseous contaminants, the first and second outlets extending into the housing from the open end thereof.

Abstract: An oil filter comprising a housing opened at one end, a first separator unit in the housing for removing solid contaminants from the oil, a mount block for the housing and a second separator unit for removing gaseous contaminants. The first separator unit comprises a cylindrical filter element defining a central space therein, and the mount block is formed with a recess in which the second separator unit is disposed. The second separator unit includes a chamber arranged to generate a vortical flow in the oil introduced therein to thereby separate gas-rich oil which gathers in an axially central portion of the chamber, means for introducing the oil from the central space to the chamber, a first outlet member for leading the oil containing little gaseous contaminants and a second outlet member for discharging the gas-rich oil.