# US 10,480,405 B2 · Method for coupling two sub-shafts > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,480,405 B2 - Document ID: US10480405B2 - Status: Granted - Kind: B2 - Application number: 15/750,594 - Filed: 2016-06-30 - Published: 2019-01-10 - Granted: 2019-11-19 - Earliest claimed: 2015-08-14 - Assignees: Siemens Aktiengesellschaft - Applicants: Siemens Aktiengesellschaft - Inventors: Michael Winkel - Web page: https://patentgrep.com/patent/US10480405B2 ## CPC - F02C 6/02: Plural gas-turbine plants having a common power output - F01D 13/003: {with at least two independent shafts, i.e. cross-compound} - F01D 19/00: Starting of machines or engines; Regulating, controlling, or safety means in connection therewith (warming-up before starting F01D25/10; turning or inching gear F01D25/34) - F02C 7/36: Power transmission arrangements between the different shafts of the gas turbine plant, or between the gas-turbine plant and the power user ({F02C3/107 - F02C3/13 and} F02C7/32 take precedence; couplings for transmitting rotation F16D; gearing in general F16H) - F16D 48/00: External control of clutches - F16D 48/06: Control by electric or electronic means, e.g. of fluid pressure - F05D 2220/72: a steam turbine - F05D 2260/40: Transmission of power - F05D 2260/85: Starting - F05D 2260/96: Preventing, counteracting or reducing vibration or noise - F05D 2270/023: of different spools or shafts - F05D 2270/304: Spool rotational speed - F16D 2300/22: Vibration damping - F16D 2500/3021: Angle - F16D 2500/3022: Current - F16D 2500/30415: Speed of the input shaft - F16D 2500/30426: Speed of the output shaft - F16D 2500/30816: Speed of the input shaft - F16D 2500/30818: Speed change rate of the input shaft - F16D 2500/30825: Speed of the output shaft - Y02E 20/14: Combined heat and power generation [CHP] - 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) - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A method for coupling a first sub-shaft, which has a first turbomachine and a generator connected to a mains supply, to a second sub-shaft, which has a second turbomachine, by means of an overrunning clutch, has the following steps: a) rotating the second sub-shaft with a starting rotational speed which is lower than the rotational speed of the first sub-shaft; b) measuring the mains frequency of the mains supply; c) measuring a differential angle between the first sub-shaft and the second sub-shaft; d) accelerating the second sub-shaft with an acceleration value which is produced using the mains frequency measured in step b), the differential angle and the starting rotational speed, and therefore the overrunning clutch couples the two sub-shafts to each other with a previously determined target coupling angle. ## Claims ### Claim 1 A method for coupling a first sub-shaft, which has a first fluid-flow machine and a generator connected to a mains supply, to a second sub-shaft, which has a second fluid-flow machine, by means of an overrunning clutch, comprising the steps: a) rotating the second sub-shaft with an initial rotational speed which is lower than the rotational speed of the first sub-shaft; b) measuring the mains frequency of the mains supply; c) measuring a differential angle between the first sub-shaft and the second sub-shaft; d) accelerating the second sub-shaft with an acceleration value which is produced by using the mains frequency measured in step b), the differential angle and the initial rotational speed, so that the overrunning clutch couples the two sub-shafts to each other with a previously determined target coupling angle; e) measuring a new mains frequency during the accelerations of the second sub-shaft; f) in the event that the new mains frequency is different from the mains frequency measured in step b), accelerating the second sub-shaft with a changed acceleration value, which is produced by using the new mains frequency. ### Claim 2 (depends on 1) The method as claimed in claim 1, further comprising the step: g) repeating steps e) and f) at least once. ### Claim 3 (depends on 1) The method as claimed in claim 1, wherein the mains frequency is measured electrically and/or by measuring the rotational speed of the first sub-shaft. ### Claim 4 (depends on 1) The method as claimed in claim 1, further comprising the steps: b1) forming a difference between the mains frequency and a reference mains frequency; c1) determining an initial acceleration value by using the differential angle, the initial rotational speed and the reference mains frequency; wherein in step d) the acceleration value is determined by using the initial acceleration value and the difference. ### Claim 5 (depends on 1) The method as claimed in claim 1, wherein step d) is carried out as soon as the differential angle measured in step c) is equal to a reference differential angle. ### Claim 6 (depends on 5) The method as claimed in claim 5, further comprising the steps: b1) forming a difference between the mains frequency and a reference mains frequency; c1) determining an initial acceleration value by using the reference differential angle, the initial rotational speed and the reference mains frequency; wherein in step d) the acceleration value is determined by using the initial acceleration value and the difference. ### Claim 7 (depends on 1) The method as claimed in claim 1, wherein the initial rotational speed and the acceleration value are entered as set points into a rotational speed control system of the second sub-shaft. ### Claim 8 (depends on 1) The method as claimed in claim 1, wherein the first fluid-flow machine is a gas turbine and the second fluid-flow machine is a steam turbine. ### Claim 9 (depends on 1) The method as claimed in claim 1, wherein the first fluid-flow machine is a steam turbine and the second fluid-flow machine is a steam turbine. ### Claim 10 (depends on 1) The method as claimed in claim 1, further comprising the step: g) repeating steps e) and f) continuously.