Study On A Valveless Pump Driven By Magnetically Controlled Shape Memory Alloy Actuator

Precision motion and position control actuators which can provide greater forces and torques within given volume and weight are in great need in modern industry. Nowadays, more and more functional materials can be adopted to generate mechanical moving. New kinds of actuators based on smart materials are paid more attention to. Magnetically controlled shape memory alloy (MSMA) is a new type of functional material found in recent years, which has not only large shape variation and fast dynamic response but also high power density and high efficiency of electromechanical energy conversion. It will be a key material of the new kinds of intelligent actuators and sensors.In this thesis, the crystal structure and shape variation mechanism of MSMA are analyzed. The phase transition temperature and the range of working temperature of MSMA are presented. The static and dynamic characteristic of MSMA has been analyzed systematically. The relationship between the strain of MSMA and the varying of temperatures, external magnetic field and pre-stresses are ascertained.The reverse effect of the MSMA has also been studied in this thesis. The reverse effect of the MSMA is the magnetic characteristic under the external force. The experimental device for study the reverse effect of the MSMA has been self-developed. According to the test results, as a new kind of functional material, the MSMA can be used in position, speed and acceleration sensor.In this thesis, a valveless pump driven by the differential MSMA actuator is proposed. The differential control strategy can decrease exciting power, eliminate temperature influence and improve working frequency and output torque. The design principle of the differential MSMA actuator and the one-way flow mechanism and structure design of the valveless pump has been analyzed. A prototype and the control system have been developed successfully. The analysis of the magnetic field and flow field has been finished, and the preliminary test has been taken. The feasibility of the operation principle and design method of the valveless pump driven by the MSMA actuator have been proved by the analysis and test results.