# US 2020/0400070 A1 · Gas turbine engine having oil level measurement system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0400070 A1 - Document ID: US20200400070A1 - Status: Published application - Kind: A1 - Application number: 16/447,360 - Filed: 2019-06-20 - Published: 2020-12-24 - Earliest claimed: 2019-06-20 - Assignees: Pratt & Whitney Canada Corp. - Applicants: Pratt & Whitney Canada Corp. - Inventors: Richard KOSTKA; David MENHEERE - Web page: https://patentgrep.com/patent/US20200400070A1 ## CPC - F01D 25/18: Lubricating arrangements (of machines or engines in general F01M) - F02C 7/06: Arrangements of bearings (bearings F16C); Lubricating ({of turbo machines F01D25/18; of machines or} engines in general F01M) - F05D 2260/602: Drainage - F05D 2260/80: Diagnostics - F05D 2260/98: Lubrication - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - 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) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract The gas turbine engine can have an accessory gearbox having a sump; an oil tank; a user interface configured to generate a signal upon receiving a user input indicative of an oil measurement reading; and a pump configured to pump oil from the sump to the oil tank upon receiving the user input. ## Claims ### Claim 1 A gas turbine engine having in serial flow communication a compressor section, a combustor and a turbine section, the gas turbine engine comprising: an accessory gearbox having a sump; an oil tank having an oil level sensor configured to measure a level of oil in the oil tank; an indicator adapted to indicate the measured level of oil to a user; a user interface configured to generate a signal when the user reads the measured level of oil from the indicator; a pump configured to pump oil from the sump to the oil tank upon receiving the signal. ### Claim 2 (depends on 1) The gas turbine engine of claim 1 wherein the user interface is a switch configured to be automatically triggered when a moveable component is moved by the user to access the indicator. ### Claim 3 (depends on 2) The gas turbine engine of claim 2 wherein the moveable component is a cover to a sight glass across which the indicator is visually accessible. ### Claim 4 (depends on 2) The gas turbine engine of claim 2 wherein the moveable component is an oil filler cap. ### Claim 5 (depends on 1) The gas turbine engine of claim 1 wherein the user interface is a system accessible from the cockpit to display an oil level on the indicator, the indicator being a display screen in the cockpit. ### Claim 6 (depends on 1) The gas turbine engine of claim 1 wherein the sump of the auxiliary gearbox is at a low point of the gas turbine engine. ### Claim 7 (depends on 1) The gas turbine engine of claim 1 wherein the oil tank is positioned above the sump. ### Claim 8 (depends on 1) The gas turbine engine of claim 1 wherein the auxiliary gearbox has an output shaft connected to a rotor of the compressor section and turbine section via gears and via at least one power transfer shaft. ### Claim 9 (depends on 8) The gas turbine engine of claim 8 wherein therein the pump is an auxiliary pump, the gas turbine engine further comprising a scavenge pump configured for pumping oil out of the sump, the scavenge pump powered by the output shaft. ### Claim 10 (depends on 1) The gas turbine engine of claim 1 wherein an air-oil separator is provided in the auxiliary gearbox. ### Claim 11 (depends on 1) The gas turbine engine of claim 1 wherein the pump is electrically powered. ### Claim 12 A method for performing maintenance on a gas turbine engine having a core gas path, an accessory gearbox having a sump, and an oil tank, the method comprising: pumping oil from the sump into the oil tank automatically i) while the core gas path of the gas turbine engine is not in operation, and ii) contingent upon the reception of a user input from a user interface, the user input being indicative of an impending oil measurement reading by a user. ### Claim 13 (depends on 12) The method of claim 12 wherein the pumping of the oil from the sump into the oil tank is performed automatically for a given period of time following reception of the user input. ### Claim 14 (depends on 12) The method of claim 12 further comprising receiving the user input from a switch triggered by the movement of a moveable component by maintenance personnel, the maintenance personnel moving the moveable component to access an oil level indicator via a sight glass. ### Claim 15 (depends on 12) The method of claim 12 further comprising a pilot sitting in the cockpit activating the user interface to display an oil level and thereby generating the user input. ### Claim 16 (depends on 12) The method of claim 12 further comprising oil leaking from the oil tank into the accessory gearbox prior to said pumping. ### Claim 17 An oil level measurement system for an engine having an oil sump positioned below the level of oil in an oil tank, the oil level measurement system comprising: a user interface configured to generate a signal upon receiving a user input indicative of an impending oil measurement reading; a pump configured to pump oil from the sump to the oil tank upon receiving the signal. ### Claim 18 (depends on 17) The gas turbine engine of claim 17 wherein the user interface is a switch configured to be automatically triggered when a moveable component is moved by maintenance personnel to access an oil level indicator. ### Claim 19 (depends on 18) The gas turbine engine of claim 18 wherein the moveable component is a cover to a sight glass across which the oil level indicator is visually accessible. ### Claim 20 (depends on 18) The gas turbine engine of claim 18 wherein the moveable component is an oil filler cap.