# US 2016/0018286 A1 · Method for monitoring deformation of a rotating element via a monitoring device employing optical fibre, and wind turbine equipped with such a device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0018286 A1 - Document ID: US20160018286A1 - Status: Published application - Kind: A1 - Application number: 14/775,473 - Filed: 2013-03-21 - Published: 2016-01-21 - Earliest claimed: 2013-03-21 - Assignees: Osmos SA - Applicants: Osmos SA - Inventors: Bernard HODAC - Web page: https://patentgrep.com/patent/US20160018286A1 ## CPC - G01M 13/04: Bearings - F03D 17/00: Monitoring or testing of wind motors, e.g. diagnostics (testing during commissioning of wind motors F03D13/30) - G01D 5/353: influencing the transmission properties of an optical fibre - G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR - F03D: WIND MOTORS - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR ## Abstract In the field of monitoring the aging of parts subjected to a rotary movement and, more precisely, of monitoring the deformation to which a peripheral surface of a rotating part is possibly subject, an improved method is provided. The method includes: a step of emitting a light signal at a first end of an optical fibre at least one section of which runs between two points of the surface of the part; a step of measuring a characteristic of the light signal received at a second end of the optical fibre, the characteristic varying as a function of the length of the optical fibre between its ends; and a step of comparing the characteristic of the light signal to a reference signal. ## Claims ### Claim 1 A method for monitoring deformations that can occur on a surface of a part capable of undergoing a rotary movement, the method comprising: a step of emitting a light signal at a first end of an optical fibre at least one section of which is stretched between two points of the surface of the part; a step of measuring a characteristic of the light signal received at a second end of the optical fibre, said characteristic developing as a function of the length of the optical fibre between its ends; and a step of comparing the characteristic of the light signal with a reference signal. ### Claim 2 (depends on 1) The method according to claim 1, in which the section of optical fibre follows a convex portion of the surface of the part. ### Claim 3 (depends on 1) The method according to claim 1, in which the part is a rotating element of a wind turbine. ### Claim 4 (depends on 1) The method according to claim 1, in which the part is a rotating element of a turbine. ### Claim 5 (depends on 1) The method according to claim 1, in which the part is a ring of a mechanical bearing. ### Claim 6 (depends on 1) The method according to claim 1, in which a plurality of optical fibres is used, each optical fibre comprising a section stretched between two points of the surface of the part, for each optical fibre: a light signal being emitted at a first end; a characteristic of the light signal received at a second end being measured; and the characteristic of the light signal being compared with a reference signal. ### Claim 7 (depends on 6) The method according to claim 6, in which the optical signals are emitted simultaneously in each optical fibre. ### Claim 8 (depends on 6) The method according to claim 6, in which two optical fibres are used, the stretched section of a first optical fibre being arranged with respect to the stretched section of the second optical fibre according to an axial symmetry, an axis of symmetry of which is an axis of the rotary movement of the part. ### Claim 9 (depends on 6) The method according to claim 6, in which the surface is a surface of revolution an axis of revolution of which is merged with an axis of the rotary movement of the part, the stretched sections of the optical fibres being angularly distributed along the axis of revolution in order to cover a circumference of the surface of revolution. ### Claim 10 (depends on 1) The method according to claim 1, also comprising a step of transmission, by wireless link means, of each measured characteristic, or of the result of each comparison between the measured characteristic and the reference signal, or of a part of these elements. ### Claim 11 (depends on 10) The method according to claim 10, in which the step of transmission is carried out only in the case of a fault. ### Claim 12 (depends on 1) The method according to claim 1, in which the steps of emission, measurement and comparison are carried out continuously for a determined duration in order to allow monitoring of the deformations of the part for at least one complete rotation of the part. ### Claim 13 A wind turbine having a part capable of undergoing a rotary movement, and a device for monitoring deformations of the part, the monitoring device comprising: an optical fibre at least one section of which is stretched between two points of a surface of the part; a light source capable of emitting a light signal at a first end of the optical fibre; a detector capable of measuring a characteristic of the light signal received at a second end of the optical fibre, said characteristic developing as a function of the length of the optical fibre between its ends; and a processing module capable of comparing the characteristic of the light signal to a reference signal.