Gearbox assembly with lubricant extraction volume ratio

A gas turbine engine comprising:

• a turbo-engine including a compressor section, a combustion section, and a turbine section, the turbo-engine having a turbo-engine shaft that couples the compressor section to the turbine section;
• a fan section having a fan shaft;
• a gearbox assembly, the fan shaft being drivingly coupled to the turbo-engine shaft through the gearbox assembly, the gearbox assembly comprising:
• a gearbox including a plurality of gears that mesh with each other at a mesh and having a gearbox volume defined by an outer diameter of the gearbox and a gearbox length of the gearbox;
• and
• a gutter for collecting a gearbox lubricant scavenge flow from the gearbox, the gutter having a gutter volume defined by an inner surface of a gutter wall of the gutter and being characterized by a lubricant extraction volume ratio between 0.01 and 0.3, inclusive of the end points, the lubricant extraction volume ratio defined by:
• V
• G
• V
• GB
• wherein VG is the gutter volume of the gutter and VGB is the gearbox volume;
• and
• a lubrication system comprising:
• a lubricant tank that stores lubricant therein;
• a primary gearbox lubricant supply line in fluid communication with the lubricant tank, wherein the primary gearbox lubricant supply line directs the lubricant to the mesh;
• a secondary gearbox lubricant supply line in fluid communication with the lubricant tank in parallel with the primary gearbox lubricant supply line, wherein the secondary gearbox lubricant supply line directs the lubricant to the mesh;
• one or more valves disposed in at least one of the primary gearbox lubricant supply line or the secondary gearbox lubricant supply line, the one or more valves including a primary valve disposed in the primary gearbox lubricant supply line, the primary valve including a primary valve member that moves between a fully opened position and a fully closed position to modulate a mass flow rate of the lubricant through the primary gearbox lubricant supply line to the mesh and returns a portion of the lubricant to the lubricant tank when the primary valve member is between the fully opened position and the fully closed position;
• and
• a lubricant pump for supplying the lubricant to the mesh from the lubricant tank through the primary gearbox lubricant supply line and the secondary gearbox lubricant supply line in parallel.