Evaluation of Machine Tool Spindle Using Carbon Fiber Composite

Spindle is one of the most important component of machine tools because spindle's performance including thermal property and dynamic property greatly influences the accuracy and productivity in machining process. This study investigates the effect of the application of carbon fiber reinforced plastic (CFRP) to the spindle shaft on the performance of machine tool spindles. CFRP and steel spindle shafts with the same geometry were developed for fair comparison. Thermal and dynamic properties of the developed shaft and spindle unit were evaluated and compared. The experimental and simulation results showed that the CFRP spindle shaft improved the axial thermal displacement and dynamic stiffness. The axial thermal displacement was decreased to 1/3 of that of the steel spindle. The compliance was also decreased to 1/2. The design of the thermal displacement distribution around the bearing should be an important issue in the CFRP spindle for the thermal stability of the dynamic property.