# US 10,151,667 B2 · 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 10,151,667 B2 - Document ID: US10151667B2 - Status: Granted - Kind: B2 - Application number: 14/775,473 - Filed: 2013-03-21 - Published: 2016-01-21 - Granted: 2018-12-11 - Earliest claimed: 2013-03-21 - Assignees: Osmos SA - Applicants: Osmos SA - Inventors: Bernard Hodac - Web page: https://patentgrep.com/patent/US10151667B2 ## 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 fiber 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 fiber, the characteristic varying as a function of the length of the optical fiber between its ends; and a step of comparing the characteristic of the light signal to a reference signal. ## Claims ### Claim 1 A method for predicting mechanical failure of a part capable of undergoing a rotary movement, the method comprising: emitting a light signal at a first end of an optical fiber, at least one section of the optical fiber being stretched in a pre-stressed condition along at least part of a periphery of a rotation bearing of the part; extracting a received light signal made of the emitted signal having reached a second end of the optical fiber, the second end being opposed to the first end with respect to a developed length of the fiber; measuring a characteristic of the received light signal, said characteristic varying as a function of the developed length of the optical fiber between the first end and the second end of the optical fiber; plotting the measured characteristic of the received signal as a function of time; and comparing the plotted characteristic of the received light signal with a reference. ### Claim 2 (depends on 1) The method according to claim 1, in which the section of optical fiber 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 a plurality of optical fibers is used, each optical fiber comprising a section stretched between two points on the surface of the part, for each optical fiber: a light signal is emitted at a first end; a characteristic of the light signal is received at a second end being measured; and the characteristic of the light signal is compared with a reference signal. ### Claim 6 (depends on 5) The method according to claim 5, in which the optical signals are emitted simultaneously in each optical fiber. ### Claim 7 (depends on 5) The method according to claim 5, in which two optical fibers are used, the stretched section of a first optical fiber being arranged with respect to the stretched section of the second optical fiber according to an axial symmetry, an axis of symmetry of which is an axis of the rotary movement of the part. ### Claim 8 (depends on 5) The method according to claim 5, 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 fibers being angularly distributed along the axis of revolution to cover a circumference of the surface of revolution. ### Claim 9 (depends on 1) The method according to claim 1, also comprising transmitting, by wireless link means, each measured characteristic, or of the result of each comparison between the measured characteristic and the reference signal, or a part of these elements. ### Claim 10 (depends on 9) The method according to claim 9, in which the transmitting is carried out only in the case of a fault. ### Claim 11 (depends on 1) The method according to claim 1, in which the emitting, measuring and comparing steps are carried out continuously for a determined duration to allow monitoring of the deformations of the part for at least one complete rotation of the part. ### Claim 12 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 fiber at least one section of which is stretched in a pre-stressed condition along at least part of a periphery of a rotation bearing of the part; a light source capable of emitting a light signal at a first end of the optical fiber; a detector capable of measuring a characteristic of a received light signal made of the emitted signal having traveled at least up to a second end of the optical fiber, said characteristic varying as a function of the length of the optical fiber between the first and second ends of the optical fiber; and a processing module capable of plotting the measured characteristic as a function of time and comparing the plotted characteristic of the received light signal to a reference.