Characteristics of Multilayer Piezoelectric Actuator Made of HighQMaterial for Application to Ultrasonic Linear Motor

Recently, we have developed a low voltage drive ultrasonic linear motor using a L 1 -F 2 double mode stator vibrator made of multilayer piezoelectric actuators (MPAs). However, when the linear motor was continuously driven, the temperature rise of the stator vibrator was over 20°C. This is mainly because the MPA used by us is made of a low Q piezoelectric material (soft material MPA), which is usually applied due to its large piezoelectric coupling coefficient. Therefore, in order to reduce heat generation of the MPA, we tried to apply a MPA made of high Q piezoelectric material (hard material MPA), which has been little applied to date. As a result, it is clarified that the temperature rise of the hard material MPA is far less than that of a soft material MPA and therefore the temperature rise of the stator vibrator using the hard material MPA is also far less than that of the stator vibrator using a soft material MPA. Additionally, in this paper, it is reported that performances of the ultrasonic linear motor composed of hard material MPA are superior in practical application.