HPC for improved efficiency on standard machine tools by using new fluid-driven spindles

The use of fluid-driven spindles is well known for machining various components, but not in real metal cutting. Machining of larger precision components as prototypes, tools and dies requires the use of relatively large machine tools and high-performance spindles. Usually these are mechanical spindles with relatively high power, displaying a rather low maximum speed of approximately 15,000 rpm. However, in semi-finishing and finishing with HPC conditions and in micro machining, the required rotation speeds are higher and the required power is lower. This paper presents sustainability and efficiency using fluid-driven spindles for HPC on standard machine tools with small tool diameters and rotation speeds of up to 90,000 rpm using air and 30,000 rpm using the coolant flow. The fluid-driven spindle leads to a significant widening of the application range of larger machine tools and to an improvement of productivity by higher efficiency and faster tool- and spindle change, respectively.