Planetary Mill with Friction Wheels Transmission Aided by an Additional Degree of Freedom

Processing in planetary ball mills is well suited to a large number of applications because they are easy to operate and versatile, grinding faster than other mills. Research related to planetary mills are mainly about the process evaluation, and there are few studies on the mechanical design of such equipment. This paper describes the decision process in the design of an innovative planetary mill in which design for manufacture and assembly (DFMA) principles were used to provide compact equipment made of simple and standardized parts. We developed a friction wheel mechanism with an additional degree of freedom that improves transmission and facilitates assembly, reducing the need for adjustment. It can be applied to different equipment that relies on planetary motion or rotating devices. A prototype was built, and its grinding performance surpasses that of other types of traditional mill. The mean particle size of alumina powder was reduced from 4.2 µm to 0.9 µm in 60 minutes.