TEMPERATURE COMPENSATING FLEXTENSIONAL TRANSDUCER

摘要

A flextensional transducer (1 ) that can be stored at room temperature and activated and operated at an elevated temperature in excess of 200°C, comprises (i)an elongate driver (2), (ii)a flextensional housing shell (3) containing the elongate driver, comprising a pair of contact portions (4) located on opposite sides of the housing shell and in mechanical contact with the ends of the driver, and having a different coefficient of thermal expansion from that of the driver, and (iii)thermal compensating members (29); the flextensional housing shell moving by flexing on actuation, the thermal compensating members being located in, or on, parts (17) of the housing shell that move on actuation, and comprising a material having a different coefficient of thermal expansion from that of surrounding parts of the housing shell, such that as the temperature increases up to the said elevated temperature the thermal compensating members expand more or less than the said surrounding parts of the housing shell, causing the housing shell to flex so as to urge the contact portions (4) of the housing shell towards each other to compensate for the greater thermal expansion of the housing relative to that of the driver member (2).