The Alternative Drive System: Design and Development of a Cam-Driven Ball Mill

In mineral processing industries, grinding process is performed in tumbling mills that describe a class of mills delimited by a cylindrical chamber filled with balls and/or rock that rotate around its longitudinal axis. These tumbling mills range in size from small 0.3 m diameter lab mills to a 16 m diameter semi-autogenous industrial mill and are driven by chain and sprocket (lab mills), gear and pinion (pilot and industrial scale mills) and gearless drives in very large diameter mill (8 to 12 m dia.). All of these mill drives present advantages and limitations. In this work, we focus on the design and development of a ball mill with cam-driven that results in a very considerable reduction in friction by the substitution of rolling friction for sliding friction. An alternative drive system is presented that uses a newly patented speed-o-cam technology and applies it to a 5 ft diameter mill. We introduce polynomials to modify the cam profile around both the cusp and the blunt point of the profile to improve pressure angle and shock impact. We build models of mechanical systems, simulate the full-motion behavior of the models, and analyze multiple design variations. We integrate the theoretical, virtual and experimental analyses in order to design an optimal mechanical system. Moreover, the analysis of static and dynamic forces of cam mechanism is reported in the work.

Lei Geng, Master: Studied Production and Manufacture at Mechanical Engineering of McGill University, Quality Manager at Miller International LTD, UK