Design and development of a cam-driven laboratory ball mill

In mineral processing industries, grinding processes can be defined as the particles reduced in size by a combination of impact and abrasion. It 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. Tumbling mills, whether they are autogenous, semi-autogenous, ball or rod, are classed according to the nature of the discharge as centre peripheral discharge mills, end peripheral discharge mills, overflow mills, and grate discharge mills. These mills are used in at least three industries: mining, cement and metal powders industries to grind different materials (ore, clinker and metal powder) to desired quality specifications as principally described by a size distribution. 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 thesis, we focus on the design and development of a cam-driven laboratory ball mill. An alternative drive system is presented that uses a newly patented speed-o-cam technology and applies it to a 5 ft diameter lab 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 thesis