A prominent mining equipment manufacturer has developed a wide variety of Gyracone primary crusher designs. The various crushers differ in fabrication and size, however all work on the same crushing principle. During 1999, a larger scale 65” prototype of a 50” crusher, the J65, experienced a number of fatigue failures. The Sinclair Knight Merz Structural Dynamics group was engaged to evaluate design modifications to improve fatigue design life targets.
Dynamics engineers drew upon analysis results from the original casting and began an iterative program to produce a quality design. Load data, measured by Dynamics engineers on a similar crusher, was modified and applied to FEA models, and a series of design changes trialed. Each change was assessed for adequate fatigue life, casting suitability, and manufacturing or assembly constraints.
A prominent constraint was gross mass, requiring minimal addition of material where possible. This objective required the use of some innovative structural modifications to increase radial and circumferential stiffness, without the addition of substantial mass. This was achieved through “flaring” rib and fillet sections, so that material was added only where necessary.
Sinclair Knight Merz brought to the project a comprehensive design and engineering diagnostic capability. These broad problem solving and re-design skills allowed test data, loads correlation and FEA design modelling to be brought together as a single complete design service.