Researches On Direct Colling Temperature Controlling Methods Of Smart Actuator Based On Giant Magnetostrictive Material

Giant Magnetostrictive Actuator (GMA) is a novel smart actuator used for magneto-mechanical energy conversion in the field of high accuracy driving structure and precision manufacturing technology, which has the merits of high precision and high response, is now widely utilized in ultra-precision machining tool, high accuracy position control, sensors, transducer, active vibration control, etc. Piston is one of the important parts of an engine cylinder. Adopting non-circular piston hole can effectively decrease the risk of stress concentration and greatly enhance the piston’s performance; however the traditional non-circular piston hole manufacturing methods have various disadvantages. Boring tools based on smart component using flexure GMA could achieve higher performance. However, as was confirmed in the experiments, keeping a stable working temperature is crucial to the precise output of GMA.In this paper, domestic and international development history and research, application situation of giant magnetostrictive material, the research background of the application of electronic devices cooling system, as well as the thermal characteristics, thermal effect, temperature controlling methods and their performance on GMM material and GMA smart components were summarized. Additionally, a novel high thermal efficiency temperature controlling method was proposed for flexure type GMA on the basis of direct liquid cooling and solid-liquid phase change principle. Two types of direct liquid cooling temperature controlling system structures, respectively with and without phase change, were proposed specific to different working environments. Furthermore, a novel chuck-style thermal structure was designed to constitute a series of structure schemes possessing diverse specialties.The heat transfer model and the computational fluid dynamics model for our proposed schemes were constructed and analyzed. Then, the optimization of the structure size parameters for the proposed temperature controlling system was studied based on genetic algorithm. By thermal dynamics modeling and simulation, the temperature efficiencies of different schemes were obtained and the optimized structure size parameters were validated. Simulation results showed that the novel direct liquid cooling methods with multi-layer oil tunnels could provide temperature disturbance ranges of around±0.02℃for Giant Magnetostrictive Material (GMM) compared to±0.4-±0.5℃by the traditional method, the temperature rising of coil windings were limited in2.2℃as well. The novel temperature controlling methods and thermal structures will shed light on further application research and development utilizing GMM. At last, an experiment platform consists of the liquid cavity, liquid piping, relevant controlling and mearsurement hardware, circuit and software was developed. Based on the platform, equivalent experiments were conducted. Experiment results showed that the novel direct liquid cooling methods could control the temperature rising range within0.5℃～0.7℃, and provide a temperature disturbance ranges of around±0.05℃～±0.1℃for GMM, which is an improvement comparing with the traditional method.Summarizing and research prospecting were put forward afterward.