# US 10,309,307 B2 · Auxiliary oil system for negative gravity event > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,309,307 B2 - Document ID: US10309307B2 - Status: Granted - Kind: B2 - Application number: 15/185,377 - Filed: 2016-06-17 - Published: 2016-10-06 - Granted: 2019-06-04 - Earliest claimed: 2012-05-31 - Assignees: United Technologies Corporation - Applicants: United Technologies Corporation - Inventors: William G. Sheridan; Paul H. Dolman - Web page: https://patentgrep.com/patent/US10309307B2 ## CPC - F02C 7/06: Arrangements of bearings (bearings F16C); Lubricating ({of turbo machines F01D25/18; of machines or} engines in general F01M) - F01D 25/20: using lubrication pumps - F01M 1/12: Closed-circuit lubricating systems not provided for in groups F01M1/02 - F01M1/10 - F01M 11/067: {inverted, e.g. for inverted flight} - F16K 15/04: shaped as balls - F01M 2001/123: {using two or more pumps} - F01M 2011/068: {with internal reservoir} - F05D 2220/323: for aircraft propulsion, e.g. jet engines - F05D 2260/98: Lubrication - F16N 2210/02: Turbines - F16N 2210/09: for inverted flight - F16N 2210/12: Gearings - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F01M: LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING - F16K: VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING {(devices for emptying and evacuating the excess liquid in valves or conduits F16L55/07)} - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - F16N: LUBRICATING ## Abstract A method of supplying a bearing compartment with fluid includes 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. During a positive gravity condition, the pumping step is performed using a main pump arranged in the main supply passage. The main reservoir includes upper and lower portions. The main supply passage is in fluid communication with the lower portion. Fluid is provided from the main reservoir to the bearing compartment through a secondary supply passage that is fluidly connected to at least one segment of the main supply passage in response to a negative gravity condition. The secondary supply passage is in fluid communication with the upper portion. ## Claims ### Claim 1 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, wherein the providing step includes flowing fluid past a first check valve arranged in the secondary supply passage. ### Claim 2 (depends on 1) The method according to claim 1, wherein the pumping step includes flowing fluid past a second check valve in the main supply passage. ### Claim 3 (depends on 1) The method according to claim 1, wherein the providing step includes pressurizing the main reservoir to open the first check valve. ### Claim 4 (depends on 1) The method according to claim 1, wherein the pumping step includes bleeding a fluid past the first check valve to fill the secondary supply passage. ### Claim 5 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. ### Claim 6 (depends on 5) The method according to claim 5, comprising a first check valve arranged in the secondary supply passage fluidly between the main reservoir and the main supply passage. ### Claim 7 (depends on 6) The method according to claim 6, comprising a bleed passage fluidly connected to the secondary passage and configured to bypass the first check valve. ### Claim 8 (depends on 6) The method according to claim 6, wherein the main reservoir includes a vent having a pressure valve configured to maintain a desired pressure in the main reservoir and open the first check valve in the negative gravity condition. ### Claim 9 (depends on 8) The method according to claim 8, wherein the desired pressure is at least 20 psia (137.90 kPa). ### Claim 10 (depends on 6) The method according to claim 6, comprising a second check valve in the main supply passage and arranged upstream from an intersection of the main supply passage with the secondary supply passage. ### Claim 11 (depends on 5) The method according to claim 5, wherein the bearing compartment includes a sump, and a scavenge pump fluidly connecting the sump to the main reservoir. ### Claim 12 (depends on 5) The method according to claim 5, comprising a shuttle valve interconnecting the auxiliary passage and the main supply passage and arranged upstream from the auxiliary and main pumps. ### Claim 13 (depends on 5) The method according to claim 5, comprising a check valve provided in the main reservoir movable in response to the positive and negative gravity conditions. ### Claim 14 (depends on 5) The method according to claim 5, wherein the main supply passage includes an ejector fluidly connected to the secondary supply passage at an ejector throat. ### Claim 15 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.