Development Of Weight Transfer Type Heat Engine Using Shape Memory Alloy

The purpose of this study is to development weight transfer type heat engine using shape memory alloy. The shape memory springs were made from Ti-50.0 at% Ni wires of 0.8 mm in diameter. The outside diameter of coil is 12 mm and the total coils are 7. The heat treatment condition is 400 °C -1 h. The reverse transformation start temperature is 55 °C. The weight of 11.3 g, 30 g, 45 g and 112.5 g were used for the heat engine. The results are summarized as follows. (1) The engine was rotate stably in the hot water above 60 °C. (2) As the weight increase up to 40 g, the output of engine was increased. (3) The maximum output power is 40 mW at 90 °C.