# US 11,306,651 B2 · Method of operating an internal combustion engine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,306,651 B2 - Document ID: US11306651B2 - Status: Granted - Kind: B2 - Application number: 17/031,967 - Filed: 2020-09-25 - Published: 2021-01-14 - Granted: 2022-04-19 - Earliest claimed: 2017-01-18 - Assignees: Pratt & Whitney Canada Corp. - Applicants: Pratt & Whitney Canada Corp. - Inventors: Andre Julien; Edwin Schulz - Web page: https://patentgrep.com/patent/US11306651B2 ## CPC - F02B 53/02: Methods of operating - F02B 19/10: with fuel introduced partly into pre-combustion chamber, and partly into cylinder - F02B 53/10: Fuel supply; Introducing fuel to combustion space - F02D 41/0087: {Selective cylinder activation, i.e. partial cylinder operation (deceleration cut-off F02D41/123)} - F02B 2053/005: {Wankel engines} - Y02T 10/12: Improving ICE efficiencies - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A method of operating a rotary engine including a rotor engaged to a shaft and rotationally received in a housing to define a plurality of working chambers of variable volume, including delivering a pilot quantity of fuel into a pilot cavity in successive communication with the working chambers, igniting the pilot quantity of fuel within the pilot cavity, and delivering a main quantity of fuel into the working chambers downstream of the successive communication of the pilot cavity with the working chambers, where at least one of the pilot quantity and the main quantity is varied between successive rotations of the shaft. ## Claims ### Claim 1 A method of operating an internal combustion engine including a movable member engaged to a shaft and movably received in a housing to define a working chamber of variable volume, the method comprising: delivering a pilot quantity of fuel into a pilot cavity in communication with the working chamber; igniting the pilot quantity of fuel within the pilot cavity; and delivering a main quantity of fuel into the working chamber; wherein one or both of the pilot quantity and the main quantity is varied between at least two successive rotations of the shaft, wherein for each set of first, second and third successive rotations of the shaft, the main quantity is zero and the pilot quantity is greater than zero during the first rotation, the main and pilot quantities are zero during the second rotation, and the main and pilot quantities are greater than zero during the third rotation. ### Claim 2 (depends on 1) The method as defined in claim 1, wherein the delivering of the pilot quantity of fuel into the pilot cavity includes delivering the pilot quantity into a pilot subchamber. ### Claim 3 (depends on 1) The method as defined in claim 1, wherein the internal combustion engine includes a plurality of working chambers, for each of the plurality of the working chambers at least one of the pilot quantity and the main quantity is zero for at least one of the successive rotations of the shaft and greater than zero for at least another one of the successive rotations of the shaft. ### Claim 4 (depends on 1) The method as defined in claim 1, wherein the internal combustion engine includes a plurality of working chambers, for each of the plurality of the working chambers the pilot quantity is zero for one of x successive rotations of the shaft and greater than zero for the remaining x−1 successive rotations of the shaft, where x is a natural number greater than 1. ### Claim 5 (depends on 1) The method as defined in claim 1, wherein the pilot quantity is greater than zero for one of x successive rotations of the shaft and zero for at least one of the remaining x−1 successive rotations of the shaft, where x is a natural number greater than 1. ### Claim 6 (depends on 1) The method as defined in claim 1, wherein the main quantity is zero for one of x successive rotations of the shaft and greater than zero for at least one of the remaining x−1 successive rotations of the shaft, where x is a natural number greater than 1. ### Claim 7 (depends on 1) The method as defined in claim 1, wherein the internal combustion engine includes a plurality of working chambers, for each of the plurality of the working chambers the main quantity is greater than zero for one of x successive rotations of the shaft and zero for the remaining x−1 successive rotations of the shaft, where x is a natural number greater than 1. ### Claim 8 (depends on 1) The method as defined in claim 1, wherein the main quantity includes first and second successive injection pulses, and wherein one of the first and second injection pulses is omitted for one of x successive rotations of the shaft and performed for the remaining x−1 successive rotations of the shaft, where x is a natural number greater than 1. ### Claim 9 (depends on 1) The method as defined in claim 1, wherein the main quantity includes first and second successive injection pulses, and wherein one of the first and second injection pulses is performed for one of x successive rotations of the shaft and omitted for the remaining x−1 successive rotations of the shaft, where x is a natural number greater than 1. ### Claim 10 (depends on 1) The method as defined in claim 1, wherein the internal combustion engine is a Wankel engine, the movable member being a rotor having three apex portions separating a plurality of working chambers and mounted for eccentric revolutions within an internal cavity of the housing, the internal cavity having an epitrochoid shape with two lobes. ### Claim 11 A method of operating an internal combustion engine including first and second movable member assemblies and a shaft, the first and second rotor movable member assemblies including first and second movable members engaged to the shaft and movably received in a housing to define a plurality of working chambers of variable volume, the method comprising: delivering a pilot quantity of fuel into a pilot cavity; igniting the pilot quantity of fuel within the pilot cavity; and delivering a main quantity of fuel into the working chambers; wherein one or both of the pilot quantity and the main quantity of a first working chamber of the plurality of working chambers is varied between at least two successive rotations of the shaft; wherein one or both of the pilot quantity and the main quantity is different between the first and second movable member assemblies during the at least two of the successive rotations of the shaft wherein for each set of first, second and third successive rotations of the shaft, the main quantity of the first rotor assembly is zero and the pilot quantity is greater than zero during the first rotation, the main and pilot quantities of the first movable member assembly are zero during the second rotation, and the main and pilot quantities of the first movable member assembly are greater than zero during the third rotation. ### Claim 12 (depends on 11) The method as defined in claim 11, wherein the delivering of the pilot quantity of fuel into the pilot cavity includes delivering the pilot quantity into a pilot subchamber. ### Claim 13 (depends on 11) The method as defined in claim 11, wherein the at least one of the pilot quantity and the main quantity of each of the first and second movable member assemblies is zero for at least one of the successive rotations of the shaft and greater than zero for at least another one of the successive rotations of the shaft. ### Claim 14 (depends on 11) The method as defined in claim 11, wherein the pilot quantity of each of the first and second movable member assemblies is zero for one of x successive rotations of the shaft and greater than zero for the remaining x−1 successive rotations of the shaft, where x is a natural number greater than 1. ### Claim 15 (depends on 11) The method as defined in claim 11, wherein the pilot quantity of each of the first and second movable member assemblies is greater than zero for one of x successive rotations of the shaft and zero for at least one of the remaining x−1 successive rotations of the shaft, where x is a natural number greater than 1. ### Claim 16 (depends on 11) The method as defined in claim 11, wherein the main quantity of each of the first and second movable member assemblies is zero for one of x successive rotations of the shaft and greater than zero for at least one of the remaining x−1 successive rotations of the shaft, where x is a natural number greater than 1. ### Claim 17 (depends on 11) The method as defined in claim 11, wherein the main quantity of each of the first and second movable member assemblies is greater than zero for one of x successive rotations of the shaft and zero for the remaining x−1 successive rotations of the shaft, where x is a natural number greater than 1. ### Claim 18 (depends on 11) The method as defined in claim 11, wherein the main quantity of the first movable member assembly includes first and second successive injection pulses for each of the working chambers, and wherein one of the first and second injection pulses is omitted for one of x successive rotations of the shaft and performed for the remaining x−1 successive rotations of the shaft, where x is a natural number greater than 1. ### Claim 19 (depends on 11) The method as defined in claim 11, wherein the main quantity of the first movable member assembly includes first and second successive injection pulses for each of the working chambers, and wherein one of the first and second injection pulses is performed for one of x successive rotations of the shaft and omitted for the remaining x−1 successive rotations of the shaft, where x is a natural number greater than 1. ### Claim 20 (depends on 11) The method as defined in claim 11, wherein the first and second movable member rotor assemblies are Wankel engines, the first and second movable members being rotors having each three apex portions separating the working chambers and mounted for eccentric revolutions within an internal cavity of the housing, the internal cavity having an epitrochoid shape with two lobes. ### Claim 21 (depends on 11) The method as defined in claim 11, further comprising a third movable member assembly engaged to the shaft, wherein the at least one of the pilot quantity and the main quantity is different between the first, second and third movable member assemblies during the at least one of the successive rotations of the shaft.