Auxiliary oil system for negative gravity event

A method of supplying a bearing compartment with fluid, comprising the steps of:

• pumping a fluid from a main reservoir to a bearing compartment through a main supply passage, which includes one or more passage segments therein, during a positive gravity condition, the pumping step performed using a main pump arranged in the main supply passage, wherein the main reservoir includes upper and lower portions, the main supply passage is in fluid communication with the lower portion;
• and
• providing fluid from the main reservoir to the bearing compartment through a secondary supply passage, fluidly connected to at least one segment of the main supply passage, in response to a negative gravity condition, wherein the secondary supply passage is in fluid communication with the upper portion, comprising an auxiliary pump fluidly connected between an auxiliary reservoir and the bearing compartment via an auxiliary passage, wherein fluid from the main pump is configured to reach the bearing compartment before reaching the auxiliary reservoir in response to the providing fluid step.

A method of supplying a bearing compartment with fluid, comprising the steps of:

• pumping a fluid from a main reservoir to a bearing compartment with a main pump before reaching an auxiliary reservoir during a positive gravity condition, wherein the bearing compartment includes a sump and a gutter, wherein the auxiliary reservoir, the sump and the gutter are discrete from one another, and an auxiliary pump is arranged fluidly between the gutter and the sump;
• and
• supplying fluid from an upper portion of the main reservoir to the bearing compartment during a negative gravity condition.