US Patent 9765875 Lubrication systems for gearbox assemblies

A gearbox assembly includes a housing with a housing interior. A sump is disposed within a lower region of the gearbox housing. A lubricated transmission element is arranged in the housing interior above the sump. A lubricant impoundment is arranged within the housing and in series between the transmission element and the sump such that lubricant flowing in a primary lubricant flow path between the transmission element and the sump is impounded in the lubricant impoundment, thereby providing a supply of lubricant for a secondary lubricant flow path disposed within the gearbox housing.