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impaginato corretto fullone_Layout 1 13/10/15 12.09 Pagina 45 Department of Engineering, ICT and Technologies for Energy and Transport Patent Title Title Radial force transducer, in particular for rotating Radial force transducer, in particular for rotating shaft’s. shaft’s . Ref. CNR 10305 Ref. CNR 10305 Assignee(s): CNR CNR Institute: INSEAN Main Inventor: Fabrizio Ortolani Countries: IT, PCT Priority date: 28/03/2014 Abstract Abstract Radial forces measurement on rotating shaft is often a challenge. The use of strain gauges mounted Radial forces measurement on rotating shaft is often a challenge. The use of strain gauges mounted directly on the shaft requires the use of slip rings or a radio link in order to power the system and acquire directly on the shaft requires the use of slip rings or a radio link in order to power the system and acquire data. Moreover underwater applications or into a dirty environment are even more difficult to achieve. data. Moreover underwater applications or into a dirty environment are even more difficult to achieve. Object of the present invention is a custom pass thru-hole, strain gauges based, biaxial force transducer Object of the present invention is a custom pass thru hole, strain gauges based, biaxial force transducer able to quantify radial forces acting on a rotating shaft. It is designed to be mounted as shaft’s frame and able to quantify radial forces acting on a rotating shaft. It is designed to be mounted as shaft’s frame and it converts shaft’s deflections into forces measure using sensitive plates equipped with strain gauges. it converts shaft’s deflections into forces measure using sensitive plates equipped with strain gauges. Moreover, scalability and sensitivity can be changed in a wide range just modifying main body Moreover, scalability and sensitivity can be changed in a wide range just modifying main body dimensions or sensitive parts’ thickness. dimensions or sensitive parts’ thickness. Background Background The first purpose of the transducer is going to be the measure of lateral forces acting on propellers during The first purpose of the transducer is going to be the measure of lateral forces acting on propellers during model test. Usually the measure of propeller’s transversal loads are performed using dedicated model test. Usually the measure of propeller’s transversal loads are performed using dedicated instruments, that allow to study only the propeller, in so called “open water“ tests. Thus, the propeller is instruments, that allow to study only the propeller, in so called “open water“ tests. Thus, the propeller is separated from the vehicle so hull’s contributions or interactions are modeled only in theoretical are modeled only in theoretical separated from the vehicle so hull’s contributions or interactions mathematical simulations. mathematical simulations. Technology Technology The transducer’s operating principle is the conversion of the deflection of sensitive beams, caused by The transducer’s operating principle is the conversion of the deflection of sensitive beams, caused by forces on the shaft, into a voltage signal using strain gauges sensors. forces on the shaft, into a voltage signal using strain gauges sensors. The transducer is composed of independent structures, machined in order to decouple the force’s The transducer is composed of independent structures, machined in order to decouple the force’s components and eliminate effects due to bending moments. components and eliminate effects due to bending moments. Advantages and Applicatons Advantages and Applications Using this transducer is possible to perform measurements in a real operative condition, working both as a Using this transducer is possible to perform measurements in a real operative condition, working both as a frame and as measuring device. Other applications would be turbine or airfoil test into wind/cavitation frame and as measuring device. Other applications would be turbine or airfoil test into wind/cavitation tunnel, measurements of loads on structures/equipments that foresee the use of loaded rods or shafts, as tunnel, measurements of loads on structures/equipments that foresee the use of loaded rods or shafts, as automation and control system, automotive monitoring or R&D preliminary and prototyping measurements. automation and control system, automotive monitoring or R&D preliminary and prototyping Development stage Development stage A prototype is being developed and calibrated. Recently, a test session on full experimental setup - that is A prototype is being developed and calibrated. Recently, a test session on full experimental setup that is the transducer mounted on a vessel model’s shaft line - in order to measure bearing loads during free the transducer mounted on a vessel model’s shaft line in order to measure bearing loads during free 45 running maneuvering tests, has been performed and experimental data and results are going to be running maneuvering tests, has been performed and experimental data and results are going to be presented in succeeding papers. presented in succeeding papers.