Load and deflection measurement system for elastomeric bearings

Abstract

Force transducers are integrated in an elastomeric flex bearing to provide signals for determining the tension and torque upon a tension member coupled to the bearing and for computation of the azimuth and elevation of the tension member. Preferably the force transducers are mounted to or embedded in an outer metal load ring of the flex bearing and are bonded with the outer metal load ring to the elastomer of the flex bearing. The force transducer, for example, include a diaphragm bonded to the elastomer, and the diaphragm has a diameter in excess of the spacing between the outer metal load ring and the nearest laminated metal reinforcement of the bearing. In one embodiment, metal foil strain gages are bonded to the surface of the diaphragm opposite from the elastomer. In another embodiment, the diaphragm transmits pressure to hydraulic fluid between the diaphragm and the outer metal support ring. A proximity sensor sensing the position of the diaphragm with respect to the outer metal support ring can be used to detect any loss of hydraulic fluid and to calibrate the hydraulic transducer under an unknown load by injecting hydraulic fluid under pressure until the diaphragm assumes a position for which the fluid pressure is indicative of the pressure applied by the elastomer to the diaphragm.