# US 2025/0146476 A1 · Wind turbine drivetrain > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0146476 A1 - Document ID: US20250146476A1 - Status: Published application - Kind: A1 - Application number: 18/929,697 - Filed: 2024-10-29 - Published: 2025-05-08 - Earliest claimed: 2023-11-03 - Assignees: Siemens Gamesa Renewable Energy A/S - Applicants: Siemens Gamesa Renewable Energy A/S - Inventors: Andreas Rogg - Web page: https://patentgrep.com/patent/US20250146476A1 ## CPC - F03D 1/0691: {of the hub} - F03D 80/504: {of powertrains, e.g. main shafts or generators} - F03D 1/0658: {Arrangements for fixing wind-engaging parts to a hub} - F03D 15/00: Transmission of mechanical power - F03D 80/50: Maintenance or repair - F16H 57/023: Mounting or installation of gears or shafts in the gearboxes, e.g. methods or means for assembly - F05B 2230/80: Repairing, retrofitting or upgrading methods - F05B 2260/40311: of the epicyclic, planetary or differential type - F16H 2057/02034: {Gearboxes combined or connected with electric machines} - F16H 2057/02078: {for wind turbines} - F16H 2057/0235: {specially adapted to allow easy accessibility and repair} - Y02E 10/72: Wind turbines with rotation axis in wind direction - F03D: WIND MOTORS - F16H: GEARING - F05B: INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A wind turbine drivetrain is provided, including a low-speed shaft; a high-speed assembly including a planetary gearbox and a generator; a coupling assembly including a first annular part connected to the low-speed shaft, a second annular part connected to a first stage of the planetary gearbox, and a cylindrical intermediate part extending between the annular parts, a drivetrain housing arranged to enclose the low-speed shaft and the coupling assembly; having an outer access opening formed in the drivetrain housing; and an inner access opening formed in the intermediate part of the coupling assembly and arranged to align with the outer access opening to facilitate access to the interior of the coupling assembly. Also, further described is a method of performing a maintenance procedure on such a wind turbine drivetrain. ## Claims ### Claim 1 A wind turbine drivetrain comprising a low-speed shaft; a high-speed assembly comprising a planetary gearbox and a generator; a coupling assembly comprising a first annular part connected to the low-speed shaft, a second annular part connected to a first stage of the planetary gearbox, and a cylindrical intermediate part extending between the annular parts, a drivetrain housing arranged to enclose the low-speed shaft and the coupling assembly; wherein, an outer access opening formed in the drivetrain housing; an inner access opening formed in the intermediate part of the coupling assembly and arranged to align with the outer access opening to facilitate access to the interior of the coupling assembly. ### Claim 2 (depends on 1) A wind turbine drivetrain according to claim 1, wherein the first annular part is secured to the low-speed shaft by a first annular arrangement of axial fasteners. ### Claim 3 (depends on 1) A wind turbine drivetrain according to claim 1, wherein the second annular part is secured to the first stage of the planetary gearbox by a second annular arrangement of axial fasteners. ### Claim 4 (depends on 1) A wind turbine drivetrain according to claim 1, wherein the drivetrain housing comprises a housing section adapted to enclose a bearing arrangement about the low-speed shaft, and a separate housing section arranged to enclose the coupling assembly. ### Claim 5 (depends on 1) A wind turbine drivetrain according to claim 1, wherein an annular part of the coupling assembly is secured to the intermediate part of the coupling assembly by an arrangement of outer fasteners. ### Claim 6 (depends on 1) A wind turbine drivetrain according to claim 1, wherein the drivetrain housing comprises a number of apertures arranged to facilitate access to the outer fasteners. ### Claim 7 (depends on 1) A wind turbine drivetrain according to claim 1, wherein the coupling assembly comprises an arrangement of shims between the intermediate part and an annular part, and wherein a shim is dimensioned to fit through an opening of the drivetrain housing. ### Claim 8 (depends on 1) A wind turbine drivetrain according to claim 1, comprising at least one bracket arranged in the interior of the coupling assembly to support a maintenance tool. ### Claim 9 (depends on 1) A method of performing a maintenance procedure on a wind turbine drivetrain according to claim 1, comprising the steps of turning a drivetrain unit to align the inner access opening with the outer access opening; inserting a tool through the aligned openings into the coupling assembly interior; and manipulating a fastener using the tool. ### Claim 10 (depends on 9) A method according to claim 9, wherein the step of turning a drivetrain unit comprises effecting a rotation of the low-speed shaft. ### Claim 11 (depends on 1) A method according to claim 1, wherein the step of turning a drivetrain unit comprises effecting a rotation of the gearbox first stage. ### Claim 12 (depends on 1) A method according to claim 1, wherein the step of manipulating a fastener using the inserted tool comprises checking the preload of the fastener and/or adjusting the preload of the fastener. ### Claim 13 (depends on 1) A method according to claim 1, comprising a step of disconnecting an annular part from the intermediate part to facilitate rotation of a first drivetrain unit relative to a second drivetrain unit. ### Claim 14 (depends on 1) A method according to claim 1, wherein maintenance of the second annular arrangement of axial fasteners comprises steps of: mounting an auxiliary drive unit to a component of the high-speed assembly to effect a rotation of the second annular part; disconnecting the second annular part from the intermediate part; D1) actuating the auxiliary drive unit to turn the second annular part to a position in which a number of the fasteners are accessible through the aligned access opening; D2) performing maintenance on the accessible fasteners; repeating steps D1 and D2 until maintenance of the second annular arrangement of axial fasteners has been completed; and connecting the second annular part to the intermediate part. ### Claim 15 (depends on 1) A method according to claim 1, wherein maintenance of the first annular arrangement of axial fasteners comprises steps of: mounting an auxiliary drive unit to a component of the high-speed assembly to effect a rotation of the second annular part; U1) actuating the auxiliary drive unit to turn the low-speed shaft through a fraction of a revolution; U2) disconnecting the first annular part from the intermediate part; U3) actuating the auxiliary drive unit to align the access openings; U4) performing maintenance on the accessible fasteners; U5) connecting the first annular part to the intermediate part; repeating steps U1-U5 until maintenance of the first annular arrangement of axial fasteners has been completed.