Abstract: The high speed precision micro-spindle requires the tool chuck with very good balance performance and dynamic characteristic. A structural concept of the monolithic micro-tool chuck using shape memory alloy (SMA) is established. The design analysis of an application example is carried out. The influence of the centrifugal force on the clamping performance is studied through simulation. The manufacturing process of the SMA ring using TiNi (Ti49.6%，Ni50.4%) alloy for the maximum two shape memory effect is studied. The prototype is manufactured and its performance including installing operation and clamping force are tested. The results show the clamped part can be inserted or removed at a temperature of 5 ℃, and clamped at room temperature (15 ℃). The corresponding clamping force is about 8.5 N. when the heating temperature is increased to 65 ℃, the clamping force increases to 41 N. The monolithic micro-tool chuck has not only simple configuration and good balance performance, but also no adding installation error, convenient operation, easy size adjustment, so it is feasible for application in the ultra-high speed and ultra-high precision micro-spindle and other high speed precision miniature transmission device.

Key words: micro-spindle;micro-tool chuck;shape memory alloy;thermo-mechanical training process;two shape memory effect