Patent attributes
An oil storage and filtration system for an engine unit includes an on/off valve that defines an operating phase when receiving supply air and in an on position and a standby phase when in an off position or not receiving the supply air. The system also includes a fill/drain valve that defines a drain state and a fill state which respectively correspond to emptying and filling oil from/into the engine unit. The system also includes a control valve, a pressure/vacuum valve, and a storage tank. The storage tank stores oil in a pressurized condition during the fill state, a vacuum condition during the drain state, and an atmospheric condition during the standby phase. The also includes a vacuum generator in fluid communication with the storage tank during the drain state and fluidly isolated from the storage tank during the fill state.