Check valve for an engine breather assembly

A breather assembly for an engine having a crankcase, the breather assembly comprising:

• a breather housing having an inlet port in fluid communication with the crankcase and an outlet port;
• and
• a check valve disposed in the breather housing, the check valve including:
• a valve seat having a seat surface defining a seat opening, the seat opening having a seat opening cross-sectional area;
• a valve stop coupled to the valve seat and defining a stop surface;
• and
• a valve element disposed between the valve seat and the valve stop and including a first element surface and a second element surface, the valve element being sufficiently flexible to actuate between a closed position, in which the first element surface engages the seat surface of the valve seat, and an open position, in which the second element surface engages the stop surface of the valve stop, the valve element defining a passage extending from the first element surface to the second element surface when the valve element is in the closed position, the passage having a passage cross-sectional area that is approximately 5-20% of the seat opening cross-sectional area.

An engine assembly, comprising:

• a crankcase;
• a housing having an inlet port in fluid communication with the crankcase and an outlet port;
• an exhaust system fluidly communicating with the outlet port;
• and
• a check valve disposed in the housing, the check valve including:
• a valve seat having a seat surface defining a seat opening, the seat opening having a seat opening cross-sectional area;
• a valve stop coupled to the valve seat and defining a stop surface;
• and
• a valve element disposed between the valve seat and the valve stop and including a first element surface and a second element surface, the valve element being sufficiently flexible to actuate between a closed position, in which the first element surface engages the seat surface of the valve seat, and an open position, in which the second element surface engages the stop surface of the valve stop, the valve element defining a passage extending from the first element surface to the second element surface when the valve element is in the closed position, the passage having a passage cross-sectional area that is approximately 5-20% of the seat opening cross-sectional area.

A check valve for a breather assembly, the check valve comprising:

• a valve seat having a seat surface defining a seat opening, the seat opening having a seat opening cross-sectional area;
• a valve stop coupled to the valve seat and defining a stop surface;
• and
• a valve element disposed between the valve seat and the valve stop and including a first element surface and a second element surface, the valve element being sufficiently flexible to actuate between a closed position, in which the first element surface engages the seat surface of the valve seat, and an open position, in which the second element surface engages the stop surface of the valve stop, the valve element defining at least one aperture extending from the first element surface to the second element surface when the valve element is in the closed position, the at least one aperture having an aperture cross-sectional area that is approximately 5-20% of the seat opening cross-sectional area.