Abstract: An engine crankcase breather includes a housing having a lower end including an inlet opening and an upper end including an outlet opening. The inlet opening lies in a horizontal plane and the outlet opening lies in a vertical plane. A mesh filter is positioned within the housing and includes opposing inlet and outlet faces defining a mesh filter thickness. The inlet and outlet faces are parallel to the inlet opening and are positioned below a central axis through the outlet opening. A bottom wall of the housing defines a portion of the lower end and includes a downward slope toward a lip defining the inlet opening. The mesh filter is spaced above the bottom wall. The engine crankcase breather also includes a plurality of oil return openings through the lip.

Abstract: An engine crankcase breather includes a housing having a lower end including an inlet opening and an upper end including an outlet opening. The inlet opening lies in a horizontal plane and the outlet opening lies in a vertical plane. A mesh filter is positioned within the housing and includes opposing inlet and outlet faces defining a mesh filter thickness. The inlet and outlet faces are parallel to the inlet opening and are positioned below a central axis through the outlet opening. A bottom wall of the housing defines a portion of the lower end and includes a downward slope toward a lip defining the inlet opening. The mesh filter is spaced above the bottom wall. The engine crankcase breather also includes a plurality of oil return openings through the lip.

Abstract: An engine has a housing and a working member movable within an interior of the housing and separating a combustion chamber from a non-combustion chamber. Additionally, the engine may include a chamber-ventilation system that may include a passageway with a first end of the passageway connected to the non-combustion chamber and a second end of the passageway located downstream of the first end of the passageway. The chamber-ventilation system may further include a filter system disposed within the passageway. The filter system may include a filter housing and a filter disposed in the filter housing. Additionally, the chamber-ventilation system may be configured such that, during operation of the engine, gas travels from the non-combustion chamber, into the first end of the passageway, through the passageway, to the second end of the passageway.