Abstract
Sharp memory alloy (SMA) is one of the functional material which shows the shape memory effect and superelasticities. Since the shape recovery temperature of Ti-Ni system SMA is below at 373K, this alloy is expected the element of heat-engine driven by low-temperature thermal of energy. Previous SMA heat-engines have not became commonplace because of short product life. Therefore, we developed SMA spiral spring actuator to improve life cycle of SMA heat-engine, and produced the spiral spring type SMA heat-engine. However, the spiral spring type SMA heat-engine needs pumps for flowing hot and cold water into the actuator. As a result, this heat-engine become complex mechanism. Therefore, we developed and produced the planetary geared type SMA heat-engine using SMA spiral spring actuator. This engine operates by the energy of hot water when this engine is submerged in hot water. In this research, we investigated the operating characteristic of this type heat-engine.
