Research On The Screw-thread-type Piezoelectric Actuator Based On Second-order Bending Mode Coupling

Piezoelectric actuators,which based on the combination of inverse piezoelectric effect,resonant displacement amplification effect and friction drive mechanism,are a kind of non-traditional driving device aiming to transfer electric energy into mechanical energy.Its advantages of high positioning accuracy,quick response,anti-electromagnetic interference,high holding torque and power-off self-locking,make it superior for applications in biological medicine,micro-mechanical-electronic equipment,aerospace and other fields.However,the rapid development of technology puts forward more stringent requirements for the performance of piezoelectric actuators,such as lower driving voltage,smaller overall size,higher positioning accuracy and so on.In view of the above demands,we summarized the recent research status of piezoelectric actuators at home and abroad,and proposed two piezoelectric screw actuators with different structures and principles based on the second-order bending mode coupling principle,which is rarely studied by scholars,and relevant experiments were carried out.The tube-shape threaded piezoelectric actuator,which weight is only 5.7g,consists of a customized PZT ceramic tube,two nuts attached to the stator and a threaded rod.The simple and compact structure is much suitable for miniaturizat ion and integrat ion.Experiment al result s show that the threa ded motor can output a stall pulling force of about 5.0 N and a linear velo cit y of 4.9mm/s wit h no load at the driving voltage of 40 V _pp.The langevin-t ype threaded piezoelectric actuator is driven by four groups of PZT ceramic plates stacked in specific pattern to excite two orthogonal bending vibrat ion modes.Its working mechanism is similar to the tube-shape actuator.Experiment results show that the motor can output a maximum load force of about 2.0 N and a linear velo cit y of 3.3 mm/s wit h no load at the driving voltage of 250 V_pp.